Once upon a time, modal logic was castigated because it ‘had no semantics.’ Kripke, Hintikka, Kanger, and others changed all that. In a similar way, when Relevant Logic was introduced by Anderson and Belnap, it too was castigated for ‘having no semantics.’ The present overview marks a culmination of that effort. The semantic approach described here brings together a number of hitherto disparate efforts to set out formal systems for logics of relevant implication and entailment. It also makes clear (despite (...) some of our hopes and utterances) that the One True Logic does not exist. This is as true for relevant logics as Kripke et al., showed it to be for modal logics. In both cases, subtle (and not so subtle) variations on semantical postulates produce different logics in the same family. The question of which semantical postulates are correct makes no sense without further context, i.e., the questioner needs to answer the question: Correct for what? The question that does remain is: What motivates the relevant family of logics? And this is the question that is the main job for this chapter to investigate. (shrink)

The Logic R4 is obtained by adding the axiom □ → to the modal relevant logic NR. We produce a model theory for this logic and show completeness. We also show that there is a natural embedding of a Kripke model for S4 in each R4 model structure.

In my article, “Why Psychology Hasn’t Kept Its Promises” , I argued that psychology hasn’t become the science its practitioners had hoped because psychologists continue to focus on mentalistic constructs and they adhere to a methodology that emphasizes statistical inference over experimental analysis. I concluded that in order to better keep their promise of a psychological science, psychologists should return to studying the relationship between observed behavior and its context with the type of experimental analysis that characterizes the other experimental (...) sciences. In his reply, Lana suggests that there may be aspects of human social and verbal behavior that are so complex that we may not be able to carry out a solid experimental analysis, thus limiting what we can discover about our own nature. Lana concludes that the methodologies needed to understand these more complex social relationships are hermeneutic and historical rather than experimental in nature. I concur with Lana both that an experimental analysis of much of human behavior may not be possible and that psychologists must, therefore, rely on complementary descriptive, interpretive, and historical analyses. I argue, however, that the interpretive language and the historical hindsight must be based on a foundation of basic principles derived from the systematic experimental analysis of behavior. (shrink)

The Logic R4 is obtained by adding the axiom □(A v B) → (◇A v □B) to the modal relevant logic NR. We produce a model theory for this logic and show completeness. We also show that there is a natural embedding of a Kripke model for S4 in each R4 model structure.

"The professional memoir of Henry Burroughs--former president of the White House Press Photographers Association, chairman of the Senate Standing Committee for Photographers, and "shooter" for the Associated Press for thirty-three years--whose career docu.

This essay posits that psychology’s general lack of respect as a science stems from two related problems: the continued focus on conceptually vague mentalistic constructs and the adherence to a methodology that emphasizes statistical inference over experimental analysis. The lack of a thoroughgoing experimental analysis has so far prevented psychologists from discovering a set of foundational principles thus inhibiting them from being able to predict and control individual behavior. Psychologists can remake their conceptual and methodological foundations by focusing on the (...) relationship between observed behavior and its context and by adopting methods of experimentation that would aid in the discovery of orderly functional relationships. This knowledge could be used to more parsimoniously explain complex behavior, including cognitive phenomena, and to more effectively solve practical problems. (shrink)

For this reason also the question is asked, whether happiness is to be acquired by learning or by habituation or some other sort of training, or comes in virtue of some divine providence or again by chance. Now if there is any gift of the gods to men, it is reasonable that happiness should be god-given, and most surely god-given of all human things inasmuch as it is the best. But this question would perhaps be more appropriate to another inquiry; (...) happiness seems, however, even if it is not god-sent but comes as a result of virtue and some process of learning or training, to be among the most god-like things; for that which is the prize and end of virtue seems to be the best thing in the world, and something godlike... (shrink)

One of the most dominant approaches to semantics for relevant (and many paraconsistent) logics is the Routley-Meyer semantics involving a ternary relation on points. To some (many?), this ternary relation has seemed like a technical trick devoid of an intuitively appealing philosophical story that connects it up with conditionality in general. In this paper, we respond to this worry by providing three different philosophical accounts of the ternary relation that correspond to three conceptions of conditionality. We close by briefly (...) discussing a general conception of conditionality that may unify the three given conceptions. (shrink)