The iterative conception of set commonly is regarded as supporting the axioms of Zermelo-Fraenkel set theory (ZF). This paper presents a modified version of the iterative conception of set and explores the consequences of that modified version for set theory. The modified conception maintains most of the features of the iterative conception of set, but allows for some non-wellfounded sets. It is suggested that this modified iterative conception of set supports the axioms of Quine's set theory NF.

Provides an overview of Mark Sharlow's philosophical work with summaries of his positions. Includes references and links to his writings.

An archive of Mark Sharlow's two blogs, "The Unfinishable Scroll" and "Religion: the Next Version." Covers Sharlow's views on metaphysics, epistemology, mind, science, religion, and politics. Includes topics and ideas not found in his papers.

In this note I examine the two main differences between Plato's and Dennett's views of the self as an abstract object. I point out that in the presence of certain forms of ontological realism, abstract-object theories of the self are compatible with the full reality of the self. I conclude with some remarks on the relationship between ontology and ethics.

In this paper I examine Daniel M. Wegner's line of argument against the causal efficacy of conscious will, as presented in Wegner's book "The Illusion of Conscious Will" (Cambridge, MA: The MIT Press, 2002). I argue that most of the evidence adduced in the book can be interpreted in ways that do not threaten the efficacy of conscious will. Also, I argue that Wegner's view of conscious will is not an empirical thesis, and that certain views of consciousness and the (...) self are immune to Wegner's line of argument. (shrink)

This is a draft for a revised edition of Mark Sharlow's book "From Brain to Cosmos." It includes most of the material from the first edition, two shorter pieces pertaining to the book, and a detailed new introduction.

In this paper, I explore the feasibility of a realistic interpretation of the quantum mechanical path integral - that is, an interpretation according to which the particle actually follows the paths that contribute to the integral. I argue that an interpretation of this sort requires spacetime to have a branching structure similar to the structures of the branching spacetimes proposed by previous authors. I point out one possible way to construct branching spacetimes of the required sort, and I ask whether (...) the resulting interpretation of quantum mechanics is empirically testable. (shrink)

In recent years, the branching spacetime (BST) interpretation of quantum mechanics has come under study by a number of philosophers, physicists and mathematicians. This paper points out some implications of the BST interpretation for two areas of quantum physics: (1) quantum gravity, and (2) stochastic interpretations of quantum mechanics.

In this paper I examine critically the relationship between the realist and nominalist views of abstract objects. I begin by pointing out some differences between the usage of existential statements in metaphysics and the usage of such statements in disciplines outside of philosophy. Then I propose an account of existence that captures the characteristic intuitions underlying the latter kind of usage. This account implies that abstract object existence claims are not as ontologically extravagant as they seem, and that such claims (...) are immune to certain standard nominalistic criticisms. (shrink)

This paper is a critique of Richard Dawkins’ “argument from improbability” against the existence of God. This argument, which forms the core of Dawkins’ book The God Delusion, provides an interesting example of the use of scientific ideas in arguments about religion. Here I raise three objections: (1) The argument is inapplicable to philosophical conceptions of God that reduce most of God’s complexity to that of the physical universe. (2) The argument depends on a way of estimating probabilities that fails (...) for the probability of an entity that creates natural laws. (3) The argument supposes that complexity arises from past physical causes; however, some forms of complexity known to mathematics and logic do not arise in this way. After stating these three criticisms, I show that some of these same considerations undermine Dawkins’ critique of agnosticism. I close the paper with some remarks on Dawkins’ conception of God. (shrink)

We describe a first-order theory of generalized sets intended to allow a similar treatment of sets and proper classes. The theory is motivated by the iterative conception of set. It has a ternary membership symbol interpreted as membership relative to a set-building step. Set and proper class are defined notions. We prove that sets and proper classes with a defined membership form an inner model of Bernays-Morse class theory. We extend ordinal and cardinal notions to generalized sets and prove ordinal (...) and cardinal results in the theory. We prove that the theory is consistent relative to ZFC + (∃ x) [ x is a strongly inaccessible cardinal]. (shrink)

Atheists sometimes use Bertrand Russell's teapot argument, and its variants with other objects in place of the teapot, to argue for the rationality of atheism. In this paper I show that this use of the teapot argument and its variants is unacceptably circular. The circularity arises because there is indirect evidence against the objects invoked in the arguments.

This document is an edited transcript of an impromptu talk by Mark F. Sharlow. In this talk, Dr. Sharlow examines one of the common arguments for God’s existence. He suggests that this argument is wrong, but not for the reason that skeptics usually cite. Instead, he points out a deeper error — and shows that by understanding this mistake, we can gain new insights into evolution and design.

In this note, I point out some implications of the experiential principle* for the nature of the relationship between language and the world. I argue that this principle implies the existence of a certain relationship between linguistic tokens and facts, and that this relationship undermines most critiques of the referentiality of language.

Many people regard the mind as something separate from the body. This includes many religious believers, who regard personality and self as attributes of an immortal soul. Some philosophers, relying on logic instead of faith, also have taken the position that the mind is distinct from the body and is not explainable in terms of bodily processes alone. The belief that a person is composed of a mind and a body, with neither one reducible to the other, has traditionally been (...) called dualism. (shrink)

In this paper, I define and study an abstract algebraic structure, the dimensive algebra, which embodies the most general features of the algebra of dimensional physical quantities. I prove some elementary results about dimensive algebras and suggest some directions for future work.

Poetry, it is said, can reveal truth. Yet despite the best efforts of philosophers and poets to describe this truth, very few understand what kinds of truth poetry can convey.* One fact seems clear: only a few of the truths of poetry can be captured equally well in prose. Poetry also conveys truths of a different kind — truths that seem to exist on a level entirely different level from that of ordinary, factual truth. Some poems try to teach moral (...) or practical lessons that also could be stated in prose.* But this is not the kind of truth that puzzles philosophers and critics. Poetry also can tell another kind of truth — a truth that may be mystifying to scholars, but that is well known to anyone who becomes acquainted with poetry in an intimate way. This kind of truth cannot be spoken of or contemplated on the same terms as ordinary fact. What is the nature of this strange, yet familiar kind of knowledge that poetry can bring to the human mind? (shrink)

This paper is a study of a distinctively chemical notion of possibility. This is the notion of possibility that occurs in chemical discourses when chemists speak of the possibility or impossibility of achieving a given result through chemical means. This notion pertains to the possibility of processes, not of compounds, so it differs from the kind of chemical possibility mentioned in Wittgenstein's Philosophical Investigations or the kinds discussed in the literature on Putnam's Twin Earth argument. I argue that this process-oriented (...) notion of possibility cannot be reduced in a simple way to physical possibility, and that standard possible worlds semantics does not allow a natural analysis of this notion. I suggest an extension of possible worlds semantics that may overcome this limitation. I finish by pointing out some open questions about chemical possibility. (shrink)

In this set of excerpts from an earlier book, I examine some philosophical issues surrounding the whole-part relationship. I present a series of thought experiments and other arguments designed to undermine the view that wholes are "nothing but" their parts.

The four talks in this collection are based on impromptu lectures by Mark Sharlow. Explores the topics of freedom, justice, punishment, capitalism, distributism, and the limits of government.

In this paper I explore the logical relationship between the question of the reality of qualia and the problem of universals. I argue that nominalism is inconsistent with the existence of qualia, and that realism either implies or makes plausible the existence of qualia. Thus, one's position on the existence of qualia is strongly constrained by one's answer to the problem of universals.

This document consists primarily of an excerpt (chapter 14) from the author’s book From Brain to Cosmos. In that excerpt, the author uses the concept of subjective fact developed earlier in the book to address a question about consciousness: which physical systems (organisms or machines) are conscious? (This document depends heavily upon the concept of subjective fact developed in From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to (...) Cosmos first. See the last page of this document for details on how to obtain those chapters.). (shrink)

Philosophers long have noted that some sensations (particularly those of color) seem to be ineffable, or refractory to verbal description. Some proposed neurophysiological explanations of this ineffability deny the intuitive view that sensations have inherently indescribable content. The present paper suggests a new explanation of ineffability that does not have this deflationary consequence. According to the hypothesis presented here, feedback modulation of information flow in the cortex interferes with the production of narratives about sensations, thereby causing the subject to assess (...) as inadequate his or her own verbal descriptions of sensations. (shrink)

This collection serves as an introduction to the concept of subjective fact, which plays a central role in some of the author's philosophical writings. The collection contains two book chapters and a paper. The first chapter (Chapter 2 of From Brain to Cosmos) begins with an informal characterization of the concept of subjective fact. Then it fleshes out this concept with examples, gives a more precise characterization, and addresses some potential weaknesses of the concept. This chapter shows how subjective fact (...) is related to key ideas in the philosophy of mind, such as intentionality. The second chapter (Chapter 3) is a detailed study of the concept of “instance of seeming” that was introduced in Chapter 2. Chapter 3 ends with some remarks on the modal logic of subjective facts. The paper, also by the book’s author, answers some potential questions about the ideas in the two included chapters. (shrink)

In this paper I argue in defense of an important fragment of folk psychology. Specifically, I argue that many propositions about the ontology of mental states and about mental causation are true largely because of certain observable features of human linguistic behavior. I conclude that these propositions are immune to common avenues of eliminativist criticism. I compare and contrast this argument with some previous arguments about the truth of folk psychology.

In this note I examine some implications of stochastic interpretations of quantum mechanics for the concept of "charge without charge" presented by Wheeler and Misner. I argue that if a stochastic interpretation of quantum mechanics were correct, then certain shortcomings of the "charge without charge" concept could be overcome.

In this paper I propose a formalization, using modal logic, of the notion of possibility that phoneticians use when they judge speech sounds to be possible or impossible. I argue that the most natural candidate for a modal logic of phonetic possibility is the modal system T.

This document consists primarily of excerpts (chapters 5 and 10-12) from the author’s book From Brain to Cosmos. These excerpts address several traditional problems about the histories of conscious subjects, using the concept of subjective fact that the author developed earlier in the book. Topics include the persistence of conscious subjects through time, the unity or disunity of the self, and the possibility of splitting conscious subjects. (These excerpts depend heavily upon the author’s concept of subjective fact as developed in (...) From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of that book first. See the last page of this document for details on how to obtain those chapters.). (shrink)

In this paper I examine a new variant of the well-known idea that the self is an abstract object. I propose a simple model of the self as a property of temporal slices of a body's history. I argue that this model, when combined with even a modest realism with regard to properties, implies that the self has many of the chief features traditionally attributed to selves. I conclude that this model allows one to reconcile the full reality of the (...) self with even the most deflationary materialistic theories of consciousness. (shrink)

Several decades ago, Wheeler and Misner presented a model of electric charge based on the topological trapping of electric field lines in wormholes. In this paper, which does not argue for or against the "charge without charge" concept, I describe some generalizations of this model which might serve as topological analogs of color charges and electroweak charges.

This document consists primarily of excerpts (chapters 5 and 7-9) from the author’s book From Brain to Cosmos. These excerpts address some traditional philosophical problems about temporal flux and identity through time, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of an excerpt (chapter 6) from the author’s book From Brain to Cosmos. That excerpt presents an analysis of the problem of knowledge of other minds, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of an excerpt (chapter 13) from the author’s book From Brain to Cosmos. In that excerpt, the author presents a study of the notion of truth using the concept of subjective fact developed earlier in the book. The author argues that mind-body materialism is compatible with certain forms of metaphysical idealism. The chapter closes with some remarks on relativism with regard to truth. (This document depends heavily upon the concept of subjective fact developed in From Brain (...) to Cosmos. Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.). (shrink)

This document consists primarily of an excerpt (chapter 5) from the author’s book From Brain to Cosmos. That excerpt presents an analysis of personal identity through time, using the concept of subjective fact that the author developed earlier in the book. (Readers unfamiliar with that concept are strongly advised to read chapters 2 and 3 of From Brain to Cosmos first. See the last page of this document for details on how to obtain those chapters.).

This document consists primarily of an excerpt (chapter 4) from the author’s book From Brain to Cosmos. That excerpt presents a study of a specific problem about knowledge: the logical justification of one’s knowledge of the immediate past. (This document depends heavily upon the concept of subjective fact that the author developed in chapters 2 and 3 of From Brain to Cosmos. Readers unfamiliar with that concept are strongly advised to read those chapters first. See the last page of this (...) document for details on how to obtain those chapters.). (shrink)

One of the most important ongoing debates in the philosophy of mind is the debate over the reality of the first-person character of consciousness.[1] Philosophers on one side of this debate hold that some features of experience are accessible only from a first-person standpoint. Some members of this camp, notably Frank Jackson, have maintained that epiphenomenal properties play roles in consciousness [2]; others, notably John R. Searle, have rejected dualism and regarded mental phenomena as entirely biological.[3] In the opposite camp (...) are philosophers who hold that all mental capacities are in some sense computational - or, more broadly, explainable in terms of features of information processing systems.[4] Consistent with this explanatory agenda, members of this camp normally deny that any aspect of mind is accessible solely from a first-person standpoint. This denial sometimes goes very far - even as far as Dennett's claim that the phenomenology of conscious experience does not really exist. (shrink)

The year is 1965. A child stands at the top of a hill, looking out over a vast golden meadow. In the field below is a dirt trail. Bicycles sail by on the trail, carrying other children to their playful destinations. Beyond the far edge of the field is the sea. On the sea are boats and ships — distant descendants of the caravels and barkentines that once explored the unknown waters of Earth.

is not about traditional skeptical thinkers like Descartes and Hume. Instead, it is about some of the ideas of today’s ”skeptics” — people who try to debunk things that seem too odd or too spiritual. This site is not meant to encourage weird beliefs, but it might make you wonder whether skepticism is a weird belief too.

This short e-book is (in the author's words) "an attempt to open up new and better ways of thinking about God." The author draws together insights from philosophy of religion, philosophy of mind, and ontology to construct a conception of God that avoids both supernaturalism and simplistic forms of pantheism.

This note is a reply to margery bedford naylor's "a note on david lewis's realism about possible worlds" . naylor asks why, if we accept david lewis's argument for real possible worlds , we should not accept an analogous argument for impossible worlds. i argue that the latter argument is invalid on the modal realist account of possibility and thus has no force for an adherent of lewis.

takes a stand for liberty, and explores important topics such as punishment, capitalism, and the limits of government. If you are sick of the left and tired of the right, you just might like this.

This book is a collection of some of my writings that do not fit the mold of standard philosophical articles. These writings range over several topics, including religion, free will, human dignity, the nature of persons, and a few others. The longest item in the collection is an archive of my blog, The Unfinishable Scroll, as it existed when the book was put together. That blog covers many philosophical topics, including some I haven't discussed elsewhere. Also in the collection are (...) essays (formerly web-based) on topics ranging from progress, to skepticism, to metaphysics - and back again. The book even contains an archive of another, less well-known, blog of mine. (shrink)

critiques the degradation of the person in current philosophical thought. This page points out some challenges to behaviorism, eliminativism, postmodernism, and other antipersonal ideas.

The twentieth century was a century of progress. During those hundred years, humanity progressed from a world without airplanes, computers, or modern medicine to a new era in which these technological miracles were commonplace. These technical achievements were not the only accomplishments of that fateful century. There also were vast changes in social thought, with great steps forward toward human equality and freedom — the struggle for racial equality, the recognition of women's rights, and the defeat of the new, unprecedented (...) menaces of Nazism and, in many places, of Communism. (shrink)

This is not a normal book. It is a collection of transcripts of talks that I gave between the year 2003 and now. I gave most of these talks on the spur of the moment, without making notes ahead of time. (“Impromptu” is the usual term for that dangerous way of speaking.) One of the “talks” is not a transcript, but a set of notes for a talk I never gave. Any organization or order in the talks is purely coincidental—or (...) at least it’s not all my fault. (shrink)

This is a collection of articles and essays that bear on the relationship between scientific and poetical/romantic views of the world.

Mark Jago presents an original philosophical account of meaningful thought: in particular, how it is meaningful to think about things that are impossible. We think about impossible things all the time. We can think about alchemists trying to turn base metal to gold, and about unfortunate mathematicians trying to square the circle. We may ponder whether God exists; and philosophers frequently debate whether properties, numbers, sets, moral and aesthetic qualities, and qualia exist. In many philosophical or mathematical debates, when (...) one side of the argument gets things wrong, it necessarily gets them wrong. As we consider both sides of one of these philosophical arguments, we will at some point think about something that’s impossible. Yet most philosophical accounts of meaning and content hold that we can’t meaningfully think or reason about the impossible. -/- In The Impossible, Jago argues that we often gain new information, new beliefs, and, sometimes, fresh knowledge through logic, mathematics, and philosophy. That is why logic, mathematics, and philosophy are useful. We therefore require accounts of knowledge and belief, of information and content, and of meaning which allow space for the impossible. Jago’s aim in this book is to provide such accounts. He gives a detailed analysis of the concept of hyperintensionality, whereby logically equivalent contents may be distinct, and develops a theory in terms of possible and impossible worlds. Along the way, he provides a theory of what those worlds are and how they feature in our analysis of normative epistemic concepts: knowledge, belief, information, and content. (shrink)

Nondescriptivist views in many areas of philosophy have long been associated with the commitment that in contrast to other domains of discourse, there are no propositions in their particular domain. For example, the ‘no truth conditions’ theory of conditionals1 is understood as the view that conditionals don’t express propositions, noncognitivist expressivism in metaethics is understood as advocating the view that there are not really moral propositions,2 and expressivism about epistemic modals is thought of as the view that there is no (...) such thing as the proposition that Jack might be at home, over and above the proposition that Jack is at home.3 Of course, it is nearly always acknowledged that advocates of a nondescriptivist theory need not deny that there are conditional, moral, or modal propositions ‘at the end of the day’ – for if they also endorse a deflationary reading of talk about propositions, as famously advocated by Simon Blackburn, then they can employ such deflationary talk just as much as the rest of us. They just don’t appeal to propositions to do any of the work in their theories. Rather, they ‘earn the right’ to talk about propositions.4 It is the aim of this paper to upset this way of thinking about the proper attitude of nondescriptivists toward propositions, and to advocate a more constructive and in some ways more radical alternative on behalf of the nondescriptivist. I will begin by introducing and developing a set of problems that are faced by any nondescriptivist theory which tries to do without propositions. All of these problems are easily solved by any view which postulates propositions across the board, but none of them are solved by merely deflationary talk about propositions – their most promising solutions require propositions to do real theoretical work, and therefore the problems themselves remind us of and illustrate some of the important reasons why it is worth positing propositions in the first place.. (shrink)

Gaining information can be modelled as a narrowing of epistemic space . Intuitively, becoming informed that such-and-such is the case rules out certain scenarios or would-be possibilities. Chalmers’s account of epistemic space treats it as a space of a priori possibility and so has trouble in dealing with the information which we intuitively feel can be gained from logical inference. I propose a more inclusive notion of epistemic space, based on Priest’s notion of open worlds yet which contains only those (...) epistemic scenarios which are not obviously impossible. Whether something is obvious is not always a determinate matter and so the resulting picture is of an epistemic space with fuzzy boundaries. (shrink)