This chapter focuses on one of the common fallacies in Western philosophy called the 'is/ought fallacy (IOF)'. Some philosophers conclude that the IOF is not a logical problem but an epistemological one, meaning that even if inferences like this one are logically valid, they cannot be used epistemologically to warrant anyone's real‐life moral beliefs. Arguments do not warrant their conclusions unless the premises of those arguments are themselves warranted, and in the real world, they say, no one would ever (...) be warranted in believing premise. Charles Pigden argues for the illegitimacy of the move from is to ought, saying that we should understand David Hume as pointing to the conservativeness of logic. According to Pigden, logic is conservative in that “the conclusions of a valid inference are contained within the premises. You do not get out what you have not put in”. (shrink)

This article is concerned with the role empirical research can play in normative practical ethics. There is no doubt that ethical research requires some kind of collaboration between normative disciplines and empirical sciences. But many researchers hold that empirical science is only assigned a subordinate role, due to the doctrine that normative conclusions cannot be justified by descriptive premises. Scientists working in the field of ethics commonly hold, however, that the empirical sciences should play a much bigger role in ethical (...) research. The aim of this paper is to show that empirical sciences can play a substantive role in normative ethics, with no illicit inferences from is to ought. To achieve this aim, I explain Hume’s thesis. In the following sections, I am concerned with different uses of empirical data that do not imply an illicit inference from descriptive premises to a normative conclusion. The article demonstrates that there are many modes of ethical reasoning that allow for a substantive use of empirical data, and it also shows the importance of Hume’s thesis for clarifying ethical reasoning. (shrink)

Ever since its formulation by Hume, the idea of an inferential barrier between non-ethical (“is”) propositions and ethical (“ought”) propositions (also known as Hume’s is-ought thesis) has received much philosophical attention. Prior’s Paradox appears to demonstrate that the ban on “is”-“ought” inferences is violated in every possible instance, from which it follows that Hume’s is-ought thesis must be false. In this article, I will formulate a logically rigorous version of Hume’s is-ought thesis, introduce Prior-style counterexamples, (...) and suggest how they might demonstrate the falsity of Hume’s is-ought thesis, identify the substitution criterion, and develop at length the unrestricted and restricted versions of this criterion as it is applied by Pigden and Schurz. Thereafter, I will outline Schurz’s defence of the is-ought gap in accordance with his interpretation of the substitution criterion, before introducing a more sophisticated version of Prior-style objections, proposing a possible response from Pigden, identifying the costs of Pigden’s response and counter proposing a response on behalf of Schurz through an extension of his approach, and offering concluding remarks. (shrink)

The view that ‘ought’ cannot be deduced from ‘is’, credited to Hume as a major insight into the nature of morality, is surprisingly easy to refute. What they are doing is evil. Therefore, they ought not to do it. Here we have a case of deducing ‘ought’ from ‘is’. The conclusion follows, because ‘ought not’ is analytic to ‘evil’. ‘Ah, but that's just what is wrong with the example: the premise is not a pure “is”; it (...) contains an “ought”, though this does not appear explicitly.’ This is true, of course; the inference would not be valid otherwise. Still, the example shows that the is/ought principle will not do as it stands. (shrink)

We propose a critique ofnormativism, defined as the idea that human thinking reflects a normative system against which it should be measured and judged. We analyze the methodological problems associated with normativism, proposing that it invites the controversial “is-ought” inference, much contested in the philosophical literature. This problem is triggered when there are competing normative accounts (the arbitration problem), as empirical evidence can help arbitrate between descriptive theories, but not between normative systems. Drawing on linguistics as a model, (...) we propose that a clear distinction between normative systems and competence theories is essential, arguing that equating them invites an “is-ought” inference: to wit, supporting normative “ought” theories with empirical “is” evidence. We analyze in detail two research programmes with normativist features – Oaksford and Chater's rational analysis and Stanovich and West's individual differences approach – demonstrating how, in each case, equating norm and competence leads to an is-ought inference. Normativism triggers a host of research biases in the psychology of reasoning and decision making: focusing on untrained participants and novel problems, analyzing psychological processes in terms of their normative correlates, and neglecting philosophically significant paradigms when they do not supply clear standards for normative judgement. For example, in a dual-process framework, normativism can lead to a fallacious “ought-is” inference, in which normative responses are taken as diagnostic of analytic reasoning. We propose that little can be gained from normativism that cannot be achieved by descriptivist computational-level analysis, illustrating our position with Hypothetical Thinking Theory and the theory of the suppositional conditional. We conclude that descriptivism is a viable option, and that theories of higher mental processing would be better off freed from normative considerations. (shrink)

The view that ‘ought’ cannot be deduced from ‘is’, credited to Hume as a major insight into the nature of morality, is surprisingly easy to refute. What they are doing is evil. Therefore, they ought not to do it. Here we have a case of deducing ‘ought’ from ‘is’. The conclusion follows, because ‘ought not’ is analytic to ‘evil’. ‘Ah, but that's just what is wrong with the example: the premise is not a pure “is”; it (...) contains an “ought”, though this does not appear explicitly.’ This is true, of course; the inference would not be valid otherwise. Still, the example shows that the is/ought principle will not do as it stands. (shrink)

What is an inference and when is an inference deductive rather than inductive, abductive, etc. The goal of this paper is precisely to determine what is that we, humans, do when we engage in deduction, i.e., whether there is something that satisfies both our pre-theoretical intuitions and theoretical presuppositions about deduction, as a cognitive process. The paper is structured in two parts: the first one deals with the issue of what is an inference. There, I will defend (...) the hypothesis that an inference is a causal process where an initial cognitive state causes another in such a way that the causal translation depends essentially on the content of the involved states. In other words, in an inference, a mental state A causes another B, partially because they have the content they have. Based on the conclusion from the first part, I will develop an account of deductive inference in the second part of the article. In order to achieve this, I will start by setting the stage and developing four constraints that an adequate account of deductive inference ought to satisfy. Then, I will present six different hypotheses that one might propose to characterize inferences of this kind. I have divided the proposals in two groups, the first one – which I will call the “logical proposals” – assume that whether an inference is a deduction or not depends exclusively on the content of the mental states involved in the inference, while the second – which I will call the “cognitive proposals” – reject the aforementioned assumption and instead recognize that extra cognitive information is required to determine whether an inference is a deduction or not. I will evaluate each proposal in turn, according to whether they satisfy the constraints introduced at the beginning of this second part. As a result of such evaluation, I will conclude that only one of the cognitive proposals actually satisfies the four constraints and therefore should be considered to give an adequate characterization of deductive inference. (shrink)

Some philosophers think that there is a gap between is and ought which necessarily makes normative enquiry a different kind of thing than empirical science. This position gains support from our ability to explicate our inferential practices in a way that makes it impermissible to move from descriptive premises to a normative conclusion. But we can also explicate them in a way that allows such moves. So there is no categorical answer as to whether there is or is not (...) a gap. The question of an is-ought gap is a practical and strategic matter rather than a logical one, and it may properly be answered in different ways for different questions or at different times. (shrink)

We propose a critique of normativism, defined as the idea that human thinking reflects a normative system against which it should be measured and judged. We analyze the methodological problems associated with normativism, proposing that it invites the controversial “is-ought” inference, much contested in the philosophical literature. This problem is triggered when there are competing normative accounts (the arbitration problem), as empirical evidence can help arbitrate between descriptive theories, but not between normative systems. Drawing on linguistics as a (...) model, we propose that a clear distinction between normative systems and competence theories is essential, arguing that equating them invites an “is-ought” inference: to wit, supporting normative “ought” theories with empirical “is” evidence. We analyze in detail two research programmes with normativist features – Oaksford and Chater’s rational analysis and Stanovich and West’s individual differences approach – demonstrating how, in each case, equating norm and competence leads to an is-ought inference. Normativism triggers a host of research biases in the psychology of reasoning and decision making: focusing on untrained participants and novel problems, analyzing psychological processes in terms of their normative correlates, and neglecting philosophically significant paradigms when they do not supply clear standards for normative judgement. For example, in a dual-process framework, normativism can lead to a fallacious “ought-is” inference, in which normative responses are taken as diagnostic of analytic reasoning. We propose that little can be gained from normativism that cannot be achieved by descriptivist computational-level analysis, illustrating our position with Hypothetical Thinking Theory and the theory of the suppositional conditional. We conclude that descriptivism is a viable option, and that theories of higher mental processing would be better off freed from normative considerations. (shrink)

The two characters in this philosophical dialogue, Russell Steadman and Jules Govier, take up the meaning and significance of David Hume’s famous “is-ought gap”—the proscription on inferring a fully moral claim from any number of purely descriptive statements. Building on the recent work of Hilary Putnam and John F. Post, Jules attempts to show that Hume’s rule is of little consequence when discussing matters related to justice or morality as we encounter them in daily life. He derives his conclusion (...) from the observations that all nontrivial human discourse contains, however tacitly, some degree of embedded normativity, and that an overlapping continuum of different types of normativity permits reasonable inference from apparently pure descriptions to fully moral prescriptions. While Russell agrees that moral concepts inevitably make reference to empirical reality, he insists that, precisely in virtue of the tacit normativity of discourse, Hume’s gap persists, rendering fallacious any attempt to fashion an argumentative bridge between the two types of statements. Although the two do not resolve all of their differences, both of their positions shift significantly in response to the other’s insights. (shrink)

In the 1950's some prominent philosophers suggested a logical relation weaker than entailment between primarily descriptive statements and ethical conclusions. The paper revisits this suggestion. It examines four ways in which ethical statemnts can be supported by descriptions and evaluations. This provides a similarity bteween some kinds of reason-giving in ethics and familiar cases of logical inference, making it plausible to speak of a logic. The similarity however is limited, and the strength in ethics of descriptive reasons is never (...) precise and always somewhat contestable. (Published Online October 13 2005). (shrink)

Defences of inference to the best explanation (IBE) frequently associate IBE with scientific realism, the idea that it is reasonable to believe our best scientific theories. I argue that this linkage is unfortunate. IBE does not warrant belief, since the fact that a theory is the best available explanation does not show it to be (even probably) true. What IBE does warrant is acceptance: taking a proposition as a premise in theoretical and/or practical reasoning. We ought to accept (...) our best scientific theories since they are the theories that are most likely to lead to the goal of science, which is that of knowledge. In support of this claim I invoke Bill Lycan's Panglossian reflections regarding Mother Nature.1. (shrink)

SummaryInstead of telling us why one should or should not derive an ‘ought’ from an ‘is’, most philosophers try to see whether this can or cannot be done. Since there are no clearly stated rules of inference for the ordinary language, the is‐ought dichotomy is re‐examined within the context of the deontic logic. This paper shows that rules like ‐AB ÓOB enables us to adopt the theorems of the propositional logic normatively, because logical standards for exactness, truth, (...) completeness, etc. are all values and conventions accepted by the deontic logicians right from the beginning.RésuméLa plupart des philosophes reste attachée à une manière incorrecte de poser la question de la dichotomie entre ce qui est et ce qui devrait être. Au lieu de se demander, avec Hume, si nous avons de bonnes raisons ?on;autoriser ou ?on;interdire des raisonnements qui concluent de ľêtre au devoir être, des philosophes tels que Searle se demandent si de tels raisonnements sont possibles dans une langue naturelle. Comme, dans une telle langue, nous n'avons pas de règie univoque pour la déduction logique, j'examine la règie de la logique déontique AB OAOB selon la formalisation de Azizah al‐Hibri. Je montre que la règie ne viole pas du tout ľinterdiction de conclure ?on;énonces de faits à des énoncés normatifs. Car dans la logique déontique, les règies et les théorèmes de la logique des propositions sont utilisés dans un sens normatif.ZusammenfassungIn bezug auf die ‘Sein‐Sollen‐Dichotomie’ scheinen die meisten Philosophen bis jetzt auf einer falschen Fragestellung zu beharren. Anstatt wie Hume zu fragen, ob wir gute Gründe haben, Schlüsse von Sein und Sollen zuzulassen oder zu verbieten, versuchen Philosophen wie etwa Searle festzustellen, ob wir dies im Rahmen der natürlichen Sprache tun konnen. Da wir in der natürlichen Sprache keine eindeutige Regel für logische Schlüsse haben, wird die Regel der deontischen Logik nach der Formalisierung von Azizah al‐Hibri untersucht. Es wird gezeigt, dass die Regel keineswegs das Verbot, von 1st‐Sätzen auf Soll‐Sätze zu schliessen, verletzt. Denn in der deontischen Logik werden die Regeln und Theoreme der Satzlogik in einem norrnativen Sinn gebraucht. (shrink)

It is well known that the process of scientific inquiry, according to Peirce, is drivenby three types of inference, namely abduction, deduction, and induction. What isbehind these labels is, however, not so clear. In particular, the common identificationof abduction with Inference to the Best Explanation (IBE) begs the question,since IBE appears to be covered by Peirce's concept of induction, not that of abduction.Consequently, abduction ought to be distinguished from IBE, at least on Peirce's account. The main aim (...) of the paper, however, is to show that this distinction is most relevant with respect to current problems in philosophy of science and epistemology (like attempts to supply suitable notions of realism and truth as well as related concepts like coherence and unification). In particular, I also try to show that (and in what way) Peirce's inferential triad can function as a method that ensures both coherence and correspondence. It is in this respect that his careful distinction between abduction and induction (or IBE) ought to be heeded. (shrink)

It is well known that the process of scientific inquiry, according to Peirce, is drivenby three types of inference, namely abduction, deduction, and induction. What isbehind these labels is, however, not so clear. In particular, the common identificationof “abduction” with “Inference to the Best Explanation” (IBE) begs the question,since IBE appears to be covered by Peirce's concept of induction, not that of abduction.Consequently, abduction ought to be distinguished from IBE, at least on Peirce's account. The main aim (...) of the paper, however, is to show that this distinction is most relevant with respect to current problems in philosophy of science and epistemology (like attempts to supply suitable notions of realism and truth as well as related concepts like coherence and unification). In particular, I also try to show that (and in what way) Peirce's inferential triad can function as a method that ensures both coherence and correspondence. It is in this respect that his careful distinction between abduction and induction (or IBE) ought to be heeded. (shrink)

This paper critically examines a formal argument against deducing ‘ought’-judgments from ‘is’-judgments, an argument suggested by a literal reading of a famous passage in Hume'sTreatise of Human Nature. According to this argument, judgments of the two kinds have different logical structures (i.e., their subjects are differently related to their predicates) and this difference disallows cross-categorical deductive inferences. I draw on Fregean accounts of the ‘is’- copula and on syntactical interpretations of ‘ought’-judgments that have become standard in deontic logic (...) to argue that twentieth century work in philosophical grammar and logic casts doubt on all three of the argument's premises. (shrink)

Originally identified by Hume, the validity of is–ought inference is much debated in the meta-ethics literature. Our work shows that inference from is to ought typically proceeds from contextualised, value-laden causal utility conditional, bridging into a deontic conclusion. Such conditional statements tell us what actions are needed to achieve or avoid consequences that are good or bad. Psychological research has established that people generally reason fluently and easily with utility conditionals. Our own research also has shown (...) that people’s reasoning from is to ought is pragmatically sensitive and adapted to achieving the individual’s goals. But how do we acquire the necessary deontic rules? In this paper, we provide a rationale for this facility linked to Evans’s framework of dual mind rationality. People have an old mind which derives its rationality by repeating what has worked in the past, mostly by experiential learning. New mind rationality, in contrast, is evolutionarily recent, uniquely developed in humans, and draws on our ability to mentally simulate hypothetical events removed in time and place. We contend that the new mind achieves its goals by inducing and applying deontic rules and that a mechanism of deontic introduction evolved for this purpose. (shrink)

Since Hume, many ethicists have assumed that inferring normative claims from descriptive claims is fallacious. Some classic examples that illustrate this fact are those in which everyone commits some act, but we do not therefore conclude that it is the right thing to do. Everyone may jump off a bridge, asserts your mother, but that does not entail that you should. However, not all such claims illustrate this. In fact, some of them illustrate precisely the opposite claim. For example, consider (...) the person who repeatedly bemoans the unfairness or sadness of dying, and who is often faced with the response that this happens to everyone. What should she do? One plausible response is that she should accept the fact that this occurs and make her peace with it, an unequivocally normative directive. This example, then, is a prima facie counterexample to the infamous gap between is-claims and ought-claims. (shrink)

This thesis brings together two concerns. The first is the nature of inference—what it is to infer—where inference is understood as a distinctive kind of conscious and self-conscious occurrence. The second concern is the possibility of doxastic agency. To be capable of doxastic agency is to be such that one is capable of directly exercising agency over one’s beliefs. It is to be capable of exercising agency over one’s beliefs in a way which does not amount to mere (...) self-manipulation. Subjects who can exercise doxastic agency can settle questions for themselves. A challenge to the possibility of doxastic agency stems from the fact that we cannot believe or come to believe “at will”, where this in turn seems to be so because belief “aims at truth”. It must be explained how we are capable of doxastic agency despite that we cannot believe or come to believe at will. On the orthodox ‘causalist’ conception of inference for an inference to occur is for one act of acceptance to cause another in some specifiable “right way”. This conception of inference prevents its advocates from adequately seeing how reasoning could be a means to exercise doxastic agency, as it is natural to think it is. Suppose, for instance, that one reasons and concludes by inferring where one’s inference yields belief in what one infers. Such an inference cannot be performed at will. We cannot infer at will when inference yields belief any more than we can believe or come to believe at will. When it comes to understanding the extent to which one could be exercising agency in such a case the causalist conception of inference suggests that we must look to the causal history of one’s concluding act of acceptance, the nature of the act’s being determined by the way in which it is caused. What results is a picture on which such reasoning as a whole cannot be action. We are at best capable of actions of a kind which lead causally to belief fixation through “mental ballistics”. The causalist account of inference, I argue, is in fact either inadequate or unmotivated. It either fails to accommodate the self-consciousness of inference or is not best placed to play the very explanatory role which it is put forward to play. On the alternative I develop when one infers one’s inference is the conscious event which is one’s act of accepting that which one is inferring. The act’s being an inference is determined, not by the way it is caused, but by the self-knowledge which it constitutively involves. This corrected understanding of inference renders the move from the challenge to the possibility of doxastic agency to the above ballistics picture no longer tempting. It also yields an account of how we are capable of exercising doxastic agency by reasoning despite being unable to believe or come to believe at will. In order to see how such reasoning could amount to the exercise of doxastic agency it needs to be conceived of appropriately. I suggest that paradigm reasoning which potentially amounts the exercise of doxastic agency ought to be conceived of as primarily epistemic agency—agency the aim of which is knowledge. With inference conceived as suggested, I argue, it can be seen how to engage in such reasoning can just be to successfully exercise such agency. (shrink)

Frank Snare had a puzzle. Noncognitivism implies No-Ought-From-Is but No- Ought-From-Is does not imply non-cognitivism. How then can we derive non-cognitivism from No-Ought-From-Is? Via an abductive argument. If we combine non-cognitivism with the conservativeness of logic (the idea that in a valid argument the conclusion is contained in the premises), this implies No-Ought-From-Is. Hence if No-Ought-From-Is is true, we can arrive at non-cognitivism via an inference to the best explanation. With prescriptivism we can make (...) this argument more precise. I develop an account of imperative consequence that underwrites Hare’s principle that you cannot derive imperatives from indicatives. Thus if moral judgments contain an imperative component, it will be impossible to derive moral conclusions from indicative or non-moral premises. Given this account of imperative consequence, we can explain No-Ought-From-Is without appealing to anything as nebulous as the conservativeness of logic. Hence if No-Ought-From-Is is true, we have an inference to the best explanation for prescriptivism. Both lines of argument face problems from Prior. Given Prior’s counterexamples, No-Ought-From-Is as originally conceived is false. The version that survives is No-Non-Vacuous-Ought-From-Is. But the best explanation of this does not include non-cognitivism. With prescriptivism it is worse. For the version of No-Ought-From-Is that prescriptivism ‘explains’ – that is, the version of No-Ought-From-Is that prescriptivism implies – would exclude Prior’s counter-examples to Autonomy as invalid. But they are not invalid. Thus Prior’s counter-examples to No-Ought-From- Is refute prescriptivism. Thus from 1960 onwards R. M.Hare was a dead philosopher walking. But if non-cognitivism cannot be derived from No-Ought-From-Is, this suggests that it is not what Hume was trying to prove. I argue that what Hume was trying to prove is that moral truths are not demonstrable. To be demonstrable, a proposition must be either self-evident or logically derivable from self-evident propositions. By Treatise 3.1.1.27, Hume had proved to his own satisfaction that no moral propositions are self-evident. That leaves open the possibility that they are logically derivable from self-evident but NON-moral propositions. The point of No-Ought-From-Is was to exclude this possibility. If you cannot logically derive moral conclusions from non-moral premises, you cannot demonstrate the truths of morality by deriving them from self-evident but NON-moral truths. I also discuss why Hume abandoned No-Ought-From-Is in the EPM. He had no need of it since he thought he had a proof that (with some exceptions) no nontrivial truths are demonstrable. Hence no non-trivial MORAL truths are demonstrable. No-Ought-From-Is drops out as unnecessary. (shrink)

Kant’s attempts to formulate a conception of the harmony of nature and freedom have two logical presuppositions. The first presupposition is separation of ought and is, which provides a logical formulation of the separation of freedom and nature. Kant might well have settled on the view that the separation between nature and freedom cannot be bridged. Why did Kant attempt to overcome said separation? The second presupposition of Kant’s project to bridge nature and freedom involves an ought→can (...) class='Hi'>inference, stating that moral obligation implies the possibility of its fulfillment. There are at least two ways this inference can be understood. There is a weak sense of the inference, stating that no one is obliged to do the impossible. There is also a very strong sense of the inference, stating that if a moral obligation is found to obtain, it must then be possible to fulfill it. Kant interprets the ought→can inference in this strong as well as in the weak sense. Nature, the law-governed totality of what exists, must be understood as able to provide a suitable field for moral realization. The isomorphism between the lawfulness of nature and that of moral freedom animate Kant’s account of moral judgment, and will provide the main focus of the current investigation. Kant conceives of nature and freedom as twin kingdoms, thus providing a theoretical model validating this ought→can inference. The weaker sense of this ought→can inference does justice to moral judgment without requiring the awesome task of bridging nature and freedom. Why, then, should we maintain the strong ought→can inference in our post-Kantian situation? I suggest that Kant’s insistence on the strong ought→can inference may yield an ethical approach to the ever more powerful ways in which human beings technologically transform nature, including human nature itself. (shrink)

Kant’s attempts to formulate a conception of the harmony of nature and freedom have two logical presuppositions. The first presupposition is separation of ought and is, which provides a logical formulation of the separation of freedom and nature. Kant might well have settled on the view that the separation between nature and freedom cannot be bridged. Why did Kant attempt to overcome said separation? The second presupposition of Kant’s project to bridge nature and freedom involves an ought→can (...) class='Hi'>inference, stating that moral obligation implies the possibility of its fulfillment. There are at least two ways this inference can be understood. There is a weak sense of the inference, stating that no one is obliged to do the impossible. There is also a very strong sense of the inference, stating that if a moral obligation is found to obtain, it must then be possible to fulfill it. Kant interprets the ought→can inference in this strong as well as in the weak sense. Nature, the law-governed totality of what exists, must be understood as able to provide a suitable field for moral realization. The isomorphism between the lawfulness of nature and that of moral freedom animate Kant’s account of moral judgment, and will provide the main focus of the current investigation. Kant conceives of nature and freedom as twin kingdoms, thus providing a theoretical model validating this ought→can inference. The weaker sense of this ought→can inference does justice to moral judgment without requiring the awesome task of bridging nature and freedom. Why, then, should we maintain the strong ought→can inference in our post-Kantian situation? I suggest that Kant’s insistence on the strong ought→can inference may yield an ethical approach to the ever more powerful ways in which human beings technologically transform nature, including human nature itself. (shrink)

Science depends on judgments of the bearing of evidence on theory. Scientists must judge whether an observation or the result of an experiment supports, disconfirms, or is simply irrelevant to a given hypothesis. Similarly, scientists may judge that, given all the available evidence, a hypothesis ought to be accepted as correct or nearly so, rejected as false, or neither. Occasionally, these evidential judgments can be made on deductive grounds. If an experimental result strictly contradicts a hypothesis, then the truth (...) of the data deductively entails the falsity of the hypothesis. In the great majority of cases, however, the connection between evidence and hypothesis is non-demonstrative, or inductive. In particular, this is so whenever a general hypothesis is inferred to be correct on the basis of the available data, since the truth of the data will not deductively entail the truth of the hypothesis. It always remains possible that the hypothesis is false even though the data are correct. (shrink)

In this article, I will provide a critical overview of the form of non-deductive reasoning commonly known as “Inference to the Best Explanation” (IBE). Roughly speaking, according to IBE, we ought to infer the hypothesis that provides the best explanation of our evidence. In section 2, I survey some contemporary formulations of IBE and highlight some of its putative applications. In section 3, I distinguish IBE from C.S. Peirce’s notion of abduction. After underlining some of the essential elements (...) of IBE, the rest of the entry is organized around an examination of various problems that IBE confronts, along with some extant attempts to address these problems. In section 4, I consider the question of when a fact requires an explanation, since presumably IBE applies only in cases where some explanation is called for. In section 5, I consider the difficult question of how we ought to understand IBE in light of the fact that among philosophers, there is significant disagreement about what constitutes an explanation. In section 6, I consider different strategies for justifying the truth-conduciveness of the explanatory virtues, e.g., simplicity, unification, scope, etc., criteria which play an indispensable role in any given application of IBE. In section 7, I survey some of the most recent literature on IBE, much of which consists of investigations of the status of IBE from the standpoint of the Bayesian philosophy of science. (shrink)

The deviation of mathematical proof—proof in mathematical practice—from the ideal of formal proof—proof in formal logic—has led many philosophers of mathematics to reconsider the commonly accepted view according to which the notion of formal proof provides an accurate descriptive account of mathematical proof. This, in turn, has motivated a search for alternative accounts of mathematical proof purporting to be more faithful to the reality of mathematical practice. Yet, in order to develop and evaluate such alternative accounts, it appears as a (...) necessary prerequisite to first possess a clear picture of what the deviation of mathematical proof from formal proof consists in. The present work aims to contribute building such a picture by investigating the relation between the elementary steps of deduction constituting the two types of proofs—mathematical inference and logical inference. Many claims have been made in the literature regarding the relation between mathematical inference and logical inference, most of them stating that the former is lacking properties that are constitutive of the latter. Such differentiating claims are, however, usually put forward without a clear conception of the properties occurring in them, and are generally considered to be immediately justified by our direct acquaintance, or phenomenological experience, with the two types of inferences. The present study purports to advance our understanding of the relation between mathematical inference and logical inference by developing a detailed philosophical analysis of the differentiating claims, that is, an analysis of the meaning of the differentiating claims—through the properties that occur in them—as well as the reasons that support them. To this end, we provide at the outset a representative list of the different properties of logical inference that have occurred in the differentiating claims, and we notice that they all boil down to the three properties of formality, generality, and mechanicality. For each one of these properties, our analysis proceeds in two steps: we first provide precise conceptual characterizations of the different ways logical inference has been said to be formal, general, and mechanical, in the philosophical and logical literature on formal proof; we then examine why mathematical inference does not appear to be formal, general, and mechanical, for the different variations of these notions identified. Our study results in a precise conceptual apparatus for expressing and discussing the properties differentiating mathematical inference from logical inference, and provides a first inventory of the various reasons supporting the observations of those differences. The differentiating claims constitute thus a set of data that any philosophical account of mathematical inference and proof purporting to be more faithful to mathematical practice ought to be able to accommodate and explain. (shrink)

The claim that (OIC) “ought” implies “can” (i.e., you have an obligation only at times at which you can obey it) entails that (1) obligations that become infeasible are lost (i.e., you stop having an obligation when you become unable to obey it). Moreover, the claim that (2) obligations that become overridden are not always lost (i.e., sometimes you keep having an obligation when you acquire a stronger incompatible obligation) entails that (ONIM) “ought” does not imply “must” (i.e., (...) some obligations are not all-things-considered). It is standard to infer ONIM—via (2)—from the premise that becoming overridden can result in “moral residue” (e.g., in the appropriateness of feeling regret). But then, I note, one could similarly infer not-OIC—via not-(1)—from the premise that becoming infeasible can result in moral residue. So there is an argument against OIC which parallels the standard argument for ONIM. I respond by rejecting both arguments: it is a mistake to always infer from the presence of moral residue that an obligation is not lost. Then I propose new arguments both for ONIM and for OIC. (shrink)

“S ought (not) to see to it that p at t” is true iff an intention on the part of S to see to it that p at t is (in) correct. From this truth condition follows an understanding of the conceptual role of ought-claims in practical inference: ought-claims are interchangeable with intentions having the same content. From this conceptual role, it is quite clear why first-person, present-tense ought-judgments, and just those, motivate: failure to be (...) motivated is a failure of rationality. The point and purpose of 'ought' is mainly to express the results of practical reasoning performed on premises held hypothetically, an exercise of which there are many varieties. Our capacity for normative thought and language is a consequence of, and intimately related to, our capacity for practical thought. (shrink)

I will argue that a person is causally responsible for believing what she does. Through inference, she can sustain and change her perspective on the world. When she draws an inference, she causes herself to keep or to change her take on things. In a literal sense, she makes up her own mind as to how things are. And, I will suggest, she can do this voluntarily. It is in part because she is causally responsible for believing what (...) she does that there are things that she ought to believe, and that what she believes can be to her credit or discredit. I won’t pursue these ethical matters here, but will focus instead on the metaphysics that underpin them. (shrink)

Science depends on judgments of the bearing of evidence on theory. Scientists must judge whether an observation or the result of an experiment supports, disconfirms, or is simply irrelevant to a given hypothesis. Similarly, scientists may judge that, given all the available evidence, a hypothesis ought to be accepted as correct or nearly so, rejected as false, or neither. Occasionally, these evidential judgments can be make on deductive grounds. If an experimental result strictly contradicts a hypothesis, then the truth (...) of the evidence deductively entails the falsity of the hypothesis. In the great majority of cases, however, the connection between evidence and hypothesis is nondemonstrative or inductive. In particular, this is so whenever a general hypothesis is inferred to be correct on the basis of the available data, since the truth of the data will not deductively entail the truth of the hypothesis. It always remains possible that the hypothesis is false even though the data are correct. (shrink)

Predicate nominals (e.g., “is a female”) seem to label or categorize their subjects, while their adjectival correlates (e.g., “is female”) merely attribute a property. Predicate nominals also elicit essentializing inferential judgments about inductive potential and stable explanatory membership. Data from psychology and semantics support that this distinction is robust and productive. I argue that while the difference between predicate nominals and predicate adjectives is elided by standard semantic theories, it ought not be. I then develop and defend a psychologically (...) motivated semantic account on which predicate nominals attribute kind membership and trigger a presupposition that underpins our essentialist judgments. (shrink)

There is an important disagreement in contemporary epistemology over the possibility of non-epistemic reasons for belief. Many epistemologists argue that non-epistemic reasons cannot be good or normative reasons for holding beliefs: non-epistemic reasons might be good reasons for a subject to bring herself to hold a belief, the argument goes, but they do not offer any normative support for the belief itself. Non-epistemic reasons, as they say, are just the wrong kind of reason for belief. Other epistemologists, however, argue that (...) there can be cases where non-epistemic reasons directly offer normative support for the beliefs a subject holds. -/- My aim in this paper is to remove an apparent obstacle for the view that there can be non-epistemic normative reasons for belief, by showing that the existence of non-epistemic reasons for belief does not conflict with epistemic standards for the assessment of inference. More specifically, I aim to show that the following principles are compatible: -/- Epistemic Norm of Inference (ENI): Necessarily, for all subjects, S, and inferences, I: I is a good inference for S only if S can gain a (doxastically) epistemically justified belief in I’s conclusion on the basis of I’s premises. -/- Non-Epistemic Reasons for Belief (NERB): Possibly, for some subject, S, reason, R, and belief, B: R is a good (i.e., normative) reason for S to hold B, and R is not an epistemic reason for B. -/- Guidance: For all subjects S, potential reasons R, and beliefs/actions φ: In order for R to count as a normative reason for S to φ, it must be possible for S to take R into account as relevant to the determination of whether S ought to φ. -/- One might naturally think that these principles conflict, for if there are non-epistemic reasons for belief, then they must guide deliberation, and in guiding deliberation, they would violate epistemic standards. The aim of this paper is to show that no such conflict need arise. -/- Section 2 of the paper proceeds to set out the concept of an inference, and to sketch an epistemic framework for the assessment of inferences and arguments. Section 3 sets out the distinction between normative and motivating reasons, and briefly defends the view that there can be non-epistemic reasons for beliefs. Section 4 shows that non-epistemic reasons for belief are compatible with epistemic standards for inference, because any time a reason R is a good non-epistemic reason for a subject S to hold a belief B, there is an epistemically good inference available to S which takes R as a premise and which concludes with the meta-belief that S ought to hold B. So the paper employs a level-connecting principle between normative reasons for φ-ing and epistemic reasons for believing that one ought to φ. The paper ends with clarifications of that level-connecting principle, and responses to three objections. (shrink)

This book explores the interrelation of facts and norms. How does law originate in the first place? What lies at the roots of this phenomenon? How is it preserved? And how does it come to an end? Questions like these led Georg Jellinek to speak of the “normative force of the factual” in the early 20th century, emphasizing the human tendency to infer rules from recurring events, and to perceive a certain practice not only as a fact but as a (...) norm; a norm which not only allows us to distinguish regularity from irregularity, but at the same time, to treat deviances as transgressions. Today, Jellinek’s concept still provides astonishing insights on the dichotomy of “is” and “ought to be”, the emergence of the normative, the efficacy and the defeasibility of norms, and the distinct character of what legal theorists refer to as “normativity”. It leads us back to early legal history, it connects anthropology and legal theory, and it demonstrates the interdependence of law and the social sciences. In short: it invites us to fundamentally reassess the interrelation of facts and norms from various perspectives. The contributing authors to this volume have accepted that invitation. (shrink)

There is an important disagreement in contemporary epistemology over the possibility of non-epistemic reasons for belief. Many epistemologists argue that non-epistemic reasons cannot be good or normative reasons for holding beliefs: non-epistemic reasons might be good reasons for a subject to bring herself to hold a belief, the argument goes, but they do not offer any normative support for the belief itself. Non-epistemic reasons, as they say, are just the wrong kind of reason for belief. Other epistemologists, however, argue that (...) there can be cases where non-epistemic reasons directly offer normative support for the beliefs a subject holds. My aim in this paper is to remove an apparent obstacle for the view that there can be non-epistemic normative reasons for belief, by showing that the existence of non-epistemic reasons for belief does not conflict with epistemic standards for the assessment of inferences. More specifically, I aim to show that the following principles are compatible. Epistemic norm of inference (ENI): necessarily, for all subjects S and inferences I: I is a good inference for S only if S can gain a (doxastically) epistemically justified belief in I’s conclusion on the basis of I’s premises. Non-epistemic reasons for belief (NERB): possibly, for some subject S, reason R, and belief B: R is a good (i.e., normative) reason for S to hold B, and R is not an epistemic reason for B. Guidance: for all subjects S, potential reasons R, and beliefs/actions φ: In order for R to count as a normative reason for S to φ, it must be possible for S to take R into account as relevant to the determination of whether S ought to φ. One might naturally think that these principles conflict, for if there are non-epistemic reasons for belief, then they must guide deliberation, and in guiding deliberation, they would violate epistemic standards. The aim of this paper is to show that no such conflict need arise. Section 2 of the paper sets out the concept of an inference, and sketches an epistemic framework for the assessment of inferences and arguments. Section 3 sets out the distinction between normative and motivating reasons, discusses motivational internalism about reasons, and briefly defends the view that there can be non-epistemic reasons for beliefs. Section 4 shows that non-epistemic reasons for belief are compatible with epistemic standards for inference and with a deliberative guidance constraint on normative reasons, because any time a reason R is a good non-epistemic reason for a subject S to hold a belief B, there is an epistemically good inference available to S which takes R as a premise and which concludes with the meta-belief that S ought to hold B. So the paper employs an indirect level-connecting principle between normative reasons for φ-ing and epistemic reasons for believing that one ought to φ. The paper ends with clarifications of that level-connecting principle, and responses to three objections. (shrink)

In 1935, the Nazi government introduced what came to be known as the abrogation of the pro- hibition of analogy. This measure, a feature of the new penal law, required judges to stray from the letter of the written law and to consider instead whether an action was worthy of pun- ishment according to the ‘sound perception of the people’ and the ‘underlying principle’ of existing criminal statutes. In discussions of Nazi law, an almost unanimous conclusion is that a system (...) of criminal law ought not to contain legislation of this sort. This conclusion is often based on how the abro- gation relates to the normative claim that the law ought to be predictable. In particular, it has been argued that since the law ought to be predictable, and since this type of analogy legis- lation implied, caused or contributed to the diminution of the law’s predictability, this type of legislation ought to be prohibited. In this paper, we argue that this argument is not entirely correct. While we believe that the law ought to be predictable and that there is evidence for the claim that the Nazis’ intro- duction of analogical reasoning implied, caused, or contributed to a diminution of predictability, this fact is logically too weak to ground the conclusion that necessarily a penal system ought not to contain legislation of this kind. Despite the undeniable wickedness of the Nazi penal system, this type of analogical reasoning can be made consistent with the pre- dictability of the law. We argue that consistency of this sort depends on whether the use of analogy is supplemented by certain contextual background conditions. The occurrence of these conditions blocks an inference from the fact that the law ought to be predictable to the conclusion that a penal system ought not to allow for this type of analogical reasoning. (shrink)

There are two uses of randomization in efforts to control systematic bias in experimental design: (a) Alchemical uses seek to convert unavoidable systematic errors into random errors. (b) Hygienic uses seek to reduce the prospect of the experimenter's involvement with the implementation of the experiment contributing to bias. A few remarks are made at the end of the paper about the hygienic use of randomization as a preventative against sticky fingers. The bulk of the discussion addresses the alchemical applications. The (...) thesis is that attitudes towards the cogency of Fisher's alchemical use of randomization ought to depend on views concerning statistical deduction or direct inference. (shrink)

Of all the demands that mathematics imposes on its practitioners, one of the most fundamental is that proofs ought to be correct. It has been common since the turn of the twentieth century to take correctness to be underwritten by the existence of formal derivations in a suitable axiomatic foundation, but then it is hard to see how this normative standard can be met, given the differences between informal proofs and formal derivations, and given the inherent fragility and complexity (...) of the latter. This essay describes some of the ways that mathematical practice makes it possible to reliably and robustly meet the formal standard, preserving the standard normative account while doing justice to epistemically important features of informal mathematical justification. (shrink)

One of the most persistent issues of contemporary moral theory is the possibility of inferring moral judgments from factual nonmoral judgments. Another way of stating this issue is to inquire into the possibility of inferring "ought-judgments" from "is-judgments." It is generally accepted that the first person to deny the possibility of this inference was David Hume. The denial is supposed to be articulated in the last paragraph of the section of A Treatise of Human Nature entitled "Moral Distinctions (...) not derived from Reason," pages 469-470 in the Selby-Bigge edition. Hereafter I shall refer to this paragraph, the "is-oughtparagraph," as (I-0). The purpose of this article is to show that in (I-0) Hume makes no such denial, and to outline the implications of this revelation. (shrink)

This is one of four volumes from the same press collecting Hare’s major papers. Of the six papers in this volume, two have appeared in Mind, one in the Philosophical Review, two have appeared in special collections, and only one has not been previously published. There is brief additional material appended to some of the articles and, perhaps most important, a four page bibliography of Hare’s writings. From this bibliography one can discover which of Hare’s articles appear in each of (...) the volumes of this group and also find their original location. One might thus save the cost of a volume or two for there is little doubt, considering the size and price of these books, upon what principle the publisher of this series has decided. The articles are largely a development and defense of Hare’s views of practical reason as set forth in The Language of Morals, with particular attention to the logical forms of imperatives and ought statements, and to the forms of inference valid for each. Beyond this basic theme, the collection is not particularly unified. Two fundamental impressions, however, emerge. The first is an awareness of the enormous influence of J. L. Austin on Hare’s thinking. This is evident not only in his discussion and rejection of Austin’s distinction between locutionary and illocutionary acts, but more importantly in his constant respect for ordinary usage and his resistance to ideal formalism. The second impression is that there is much to be done to develop a logic for imperative and prescriptive inferences. These papers present some basic principles for such a development but, since they are primarily defenses against criticisms of Hare’s book, there is an ad hoc character about them. What is now required is a more complete and systematic treatment of these topics. Ordinary language analysts might here make some inroads on the domain of formal logic to recall some of that logic to philosophy. The articles collected, therefore, are valuable, particularly as they encourage further development of the overlap of logic and ethics.—K. M. (shrink)

While the inference problem is widely thought to be one of the most serious problems facing non-Humean accounts of laws, Jonathan Schaffer has argued that a primitivist response straightforwardly dissolves the problem. On this basis, he claims that the inference problem is really a pseudo-problem. Here I clarify the prospects of a primitivist response to the inference problem and their implications for the philosophical significance of the problem. I argue both that it is a substantial question whether (...) this sort of response ought to be accepted and that the inference problem, contra Schaffer, remains a significant problem with important implications for the non-Humean position. I also argue that this discussion indicates grounds to be wary about applying the Schaffer-style strategy of straightforwardly dissolving problems by stipulation to other philosophical problems. (shrink)

As is well known, the Humean account of causal inference gives a central location to inference habits. Some of these habits one can discipline. Thus, one can so discipline oneself as to reason in accordance with the “rules by which to judge of causes and effects”, that is, one can discipline oneself to think scientifically, rather than, say, in accordance with the rules of prejudice, or of superstition. All such judgments, even those of science, are, however, upon the (...) Humean account fallible. Some, or rather very many, have raised the issue about how any such causal judgment or inference is justified. That is, how can such inference habits be justified, shown to be reasonable. Hume meets this challenge by arguing that there are some habits all men do and must have. Because we must have them we ought to have them. They are, therefore, justified. (shrink)

For the last 40 years or so the is/ought gap, the fact/value distinction and the naturalistic fallacy have figured prominently in ethical debates. This longevity, however, has had an adverse side effect. So familiar have they become that they—and their respective rationales—have tended to become blurred. It is the purpose of this paper to explain why they should be kept distinct.

This paper argues that three plausible principles are mutually inconsistent: One ought to assert only what one knows; If it is proper to assert some proposition q, then it is, barring special and not very common circumstances, proper to assert any proposition p from which q has been competently inferred; and Some propositions are both properly assertible and known by competent inference from propositions which one does not know. Each pair of two principles constitutes an argument against the (...) remaining principle, but which principle should one drop? (shrink)

Abstract: Any normative inferentialist view confronts a set of challenges in the form of how to account for the sort of ordinary empirical descriptive vocabulary that is involved, paradigmatically, in our noninferential perceptual responses and knowledge claims. This chapter lays out that challenge, and then argues that Sellars’ original multilayered account of such noninferential responses in the context of his normative inferentialist semantics and epistemology shows how the inferentialist can plausibly handle those sorts of cases without stretching the notion of (...) inference beyond its standard uses. Finally, it is suggested that for Sellars there were deeply naturalistic motivations for his own normative inferentialism, though the latter raises further questions as to whether this really represents, as Sellars thought, a genuinely scientific naturalist outlook on meaning and conceptual cognition. (shrink)

The logician's central concern is with the validity of argument. A logical theory ought, therefore, to provide a general criterion of validity. This book sets out to find such a criterion, and to describe the philosophical basis and the formal theory of a logic in which the premises of a valid argument are relevant to its conclusion. The notion of relevance required for this theory is obtained by an analysis of the grounds for asserting a formula in a proof.

A dynamic semantics for iffy oughts offers an attractive alternative to the folklore that Chisholm's paradox enforces an unhappy choice between the intuitive inference rules of factual and deontic detachment. The first part of the story told here shows how a dynamic theory about ifs and oughts gives rise to a nonmonotonic perspective on deontic discourse and reasoning that elegantly removes the air of paradox from Chisholm's puzzle without sacrificing any of the two detachment principles. The second part of (...) the story showcases two bonus applications of the framework suggested here: it offers a response to Forrester's gentle murder paradox and avoids Kolodny and MacFarlane's miners paradox about deontic reasoning under epistemic uncertainty. A comparison between the dynamic semantic proposal made in this paper and a more conservative approach combining a static semantics with a dynamic pragmatics is provided. (shrink)

There is no Argument that the Mind Extends On the basis of two argumentative examples plus their 'parity principle', Clark and Chalmers argue that mental states like beliefs can extend into the environment. I raise two problems for the argument. The first problem is that it is more difficult than Clark and Chalmers think to set up the Tetris example so that application of the parity principle might render it a case of extended mind. The second problem is that, even (...) when appropriate versions of the argumentative examples can be constructed, the availability of a second, internalist parity principle precludes the possibility of inferring that the mind extends. Choosing which parity principle we ought to wield would involve deciding beforehand whether or not the mind can extend. Thus Clark and Chalmers beg the question by employing their parity principle rather than the internalist one. I conclude that they fail to provide a proper argument to support the extended mind thesis. (shrink)

In this article I argue that there is a sense in which logic is empirical, and hence open to influence from science. One of the roles of logic is the modelling and extending of natural language reasoning. It does so by providing a formal system which succeeds in modelling the structure of a paradigmatic set of our natural language inferences and which then permits us to extend this structure to novel cases with relative ease. In choosing the best system of (...) those that succeed in this, we seek certain virtues of such structures such as simplicity and naturalness (which will be explained). Science can influence logic by bringing us, as in the case of quantum mechanics, to make natural language inferences about new kinds of systems and thereby extend the set of paradigmatic cases that our formal logic ought to model as simply and naturally as possible. This can alter which structures ought to be used to provide semantics for such models. I show why such a revolution could have led us to reject one logic for another through explaining why complex claims about quantum mechanical systems failed to lead us to reject classical logic for quantum logic. (shrink)