Justin Leiber

(1938 - 2016)

This spare book amply maintains the distinction of the Bradford Book series. In chapter 1 Cummins argues that the familiar deductive-nomological notion of scientific explanation only covers transitional theories and fails to give an account of explanation through property or system analysis that is pervasive in both the physical and psychological sciences. This inadequacy of the D-N view is supposed particularly injurious in the unrobust and infant science of psychology. Explanation through analysis ranges from decidedly morphological to the decidedly systemic, and from the interpretive to the descriptive. Explanation through analysis is typically an interactive two step: one gives a revealingly helpful component-function or programmatic analysis and one hopes to find an explanatory instantiation of this analysis. Psychological explanation is importantly systemic and its most challenging problem is that of finding isomorphisms between interpretive instantiations and descriptive instantiations-the hope for two-stepping isomorphisms in human psychological explanation is bio-logical, the sorts of structures that genes can determine being the likely candidates for our psychological capacities.

Westermarck proposed that humans have an incest avoidance instinct, triggered by frequent intimate contact with family members during the first several years of life. Westermarck reasons that familial incest will tend to produce less fit offspring, those humans without instinctive incest avoidance would hence have tended to die off and those with the avoidance instinct would have produced more viable offspring, and hence familial incest would be, as indeed it is, universally and instinctively avoided . Victorian Westermarck claimed this as a human adaptation. Evolutionary psychologists have generalized these claims to Pleistocene humans and their ancestors, to primates, and indeed to animals generally. Yet there is surprisingly little evidence for these claims of universal instinctive avoidance. Considerable inbreeding appears among large, territorial primates and may have been so with early humans and with their ancestors. While there is little reliable non-anecdotal evidence about incestuous behavior or the lack of it among humans, what little there is does not fit well with the Westermarck thesis

I write, as Robert Graves put it in his Oxford poetry lectures, both matador and judge, both as a novelist and as philosopher and literary theorist. Considering the present aggressive stance of literary theorists, detonating, denuding, and deconstructing the humble scrivener's offerings as if works of fiction were the shoulders of midgets on which the giants of critical theory may grind their jackboots, you will think me rash to confess to the jejune offense of novel writing, but I mean not only to confess but also to explain and justify--even, indeed, to revel--in the inversion of fiction and life that is our lot, revel, that is, in an inversion both more enduring and more significant than that between fiction and literary theory.

Paradoxes are many things. Artificial intelligence views them as viruses of the brain, strange replicators that unexpectedly exploit design possibilities. For the child, they are intellectual cartwheels, an everyday delight. For mathematicians and logicians, they reveal skeletons in the closet of reason. For philosophers and dramatists, they capture the contradictions of experience. The historian of ideas sees that they come in successive waves, surging through Classical Greece, the Renaissance and the twentieth century. Professor Leiber's user-'friendly guide to paradoxes provides an up-to-date survey of an ancient and perennial source of puzzlement. Book jacket.

That this is one of the most distinguished books in the excellent Bradford Books cognitive science/philosophy series is suggested by the March 1983 issue of Behavioral and Brain Sciences, in which we find a precis of the book, some twenty commentaries, and Dretske's replies. Physicalists and anti-physicalists in psychology have both stressed the importance of "top-down" strategies and have debated, prospectively, about the likelihood that we eventually will have suitable reductions, or explanatory instantiations, of psychological generations in neurophysiological terms. Dretske takes the more straightforward approach, starting with an avowedly physical notion of information and then trying to show how one can make, building on this foundation, a reasonable construal of knowledge, perception, and belief. Dretske starts with the following information-theoretic specification of a signal's information content: a signal r carries the information that s is F = the conditional probability of s's being F, given r, is l. Thus, to use Dretske's humble example, "My gas gauge carries the information that I still have some gas left, if and only if the conditional probability of my having some gas left, given the reading of the gauge, is l." The parenthetical clause makes the causal character of this analysis clear: the state of the source is related by physical laws to the occurrence of the signal--the gas in the tank causes the gauge reading. Insisting on the conditional probability of l has the advantage of preserving the properties of certainty, transitivity, and addition that we associate with knowledge. If the gas gauge does carry the information that my tank has gas, then my tank must have gas. If my statement that my gauge indicates gas carries the information that it does so indicate, then information flows intact from signal to signal. And finally, if the signal carries the information that s is F, and also carries the information that s is G, then it carries, at the same level of probability assigned each, the information that s is F and G. Now we can, eventually, say that K knows that s is F = K's belief that s is F is caused by the information that s is F. The "eventually" part is important, for what is most instructive and provoking about this book is the way in which Dretske lays out the steps in constructing viable construals of knowledge, perception, and belief out of the root notion of information.--Justin Leiber, The University of Houston.

A. M. Turing has bequeathed us a conceptulary including 'Turing, or Turing-Church, thesis', 'Turing machine', 'universal Turing machine', 'Turing test' and 'Turing structures', plus other unnamed achievements. These include a proof that any formal language adequate to express arithmetic contains undecidable formulas, as well as achievements in computer science, artificial intelligence, mathematics, biology, and cognitive science. Here it is argued that these achievements hang together and have prospered well in the 50 years since Turing's death.

This book, by two philosophers at Bradford University, immediately strikes the American reader with two differences in the British philosophical scene. One is the enveloping commitment to "Davidsonian linguistics" which still seems the central topic for many of Oxford's younger philosophers. In this slim volume Davidsonian semantics is thought to provide that some measure of cross-cultural understanding is possible, that humanistic descriptions of human activity are irreplaceable and unrevisable since action explanation is non-nomothetic though often causal and inferential, that collectives may have expressive but not explanatory autonomy, and that social descriptions are not irredeemably value-laden. Who would have thought Davidsonian semantics had so much blood in it? Though the Tarskian T-Convention requirement is outlined in the short introductory chapter, one is hard put to see any real connection between the insistence on model theoretic and extensional approaches and the subsequent chapters. Though the introduction briefly allows that intensional notions are to be ignored, we are later assured that we may safely ascribe one classical logic to primitives and humans generally since "only at the highly advanced level of theoretical physics has it been found necessary to experiment with different logics". Ignored are those who think mathematics itself requires an intuitionist or intensional understanding. Also ignored are the many linguists who have recently held that the vast majority of sentences in everyday speech require intensional or modal analysis. The authors also use the label "functionalism" for the view that a society is something like a biological organism rather than a collection of rational agents. One finds this usage disconcerting. Much more unfortunate is that the authors seem innocent of the rich philosophical and psychological and neurological work on mental states and psychological explanation that has grown up around the more recent usage of the term.--Justin Leiber, University of Houston.