The aim of this paper is to sketch a theory of justified belief. What I have in mind is an explanatory theory, one that explains in a general way why certain beliefs are counted as justified and others as unjustified. Unlike some traditional approaches, I do not try to prescribe standards for justification that differ from, or improve upon, our ordinary standards. I merely try to explicate the ordinary standards, which are, I believe, quite different from those of many classical, (...) e. g., ‘Cartesian’, accounts. (shrink)

One of the main goals of epistemologists is to provide a substantive and explanatory account of the conditions under which a belief has some desirable epistemic status (typically, justification or knowledge). According to the reliabilist approach to epistemology, any adequate account will need to mention the reliability of the process responsible for the belief, or truth-conducive considerations more generally. Historically, one major motivation for reliabilism—and one source of its enduring interest—is its naturalistic potential. According to reliabilists, epistemic properties can be (...) explained in terms of reliability, which in turn can be understood without reference to any unreduced epistemic notions, such as evidence or knowledge. This article begins by surveying some of the main forms of reliabilism, concentrating on process reliabilism as a theory of justification. It proceeds to review some of the main objections to reliabilism, and some of the responses that have been offered on the reliabilist’s behalf. After canvassing some recent developments in reliabilist epistemology, the article concludes by considering various cousins and spin-offs of reliabilist epistemology, including virtue reliabilism and various evidentialist-reliabilist hybrids. (shrink)

Recent clinical trials show that psychedelics such as LSD and psilocybin can be given safely in controlled conditions, and can cause lasting psychological benefits with one or two administrations. Supervised psychedelic sessions can reduce symptoms of anxiety, depression, and addiction, and improve well-being in healthy volunteers, for months or even years. But these benefits seem to be mediated by "mystical" experiences of cosmic consciousness, which prompts a philosophical concern: do psychedelics cause psychological benefits by inducing false or implausible beliefs about (...) the metaphysical nature of reality? This book is the first scholarly monograph in English devoted to the philosophical analysis of psychedelic drugs. Its central focus is the apparent conflict between the growing use of psychedelics in psychiatry and the philosophical worldview of naturalism. Within the book, Letheby integrates empirical evidence and philosophical considerations in the service of a simple conclusion: this "Comforting Delusion Objection" to psychedelic therapy fails. While exotic metaphysical ideas do sometimes come up, they are not, on closer inspection, the central driver of change in psychedelic therapy. Psychedelics lead to lasting benefits by altering the sense of self, and changing how people relate to their own minds and lives-not by changing their beliefs about the ultimate nature of reality. The upshot is that a traditional conception of psychedelics as agents of insight and spirituality can be reconciled with naturalism (the philosophical position that the natural world is all there is). Controlled psychedelic use can lead to genuine forms of knowledge gain and spiritual growth-even if no Cosmic Consciousness or transcendent divine Reality exists. Philosophy of Psychedelics is an indispensable guide to the literature for researchers already engaged in the field of psychedelic psychiatry, and for researchers-especially philosophers-who want to become acquainted with this increasingly topical field. (shrink)

Bayesian reverse-engineering is a research strategy for developing three-level explanations of behavior and cognition. Starting from a computational-level analysis of behavior and cognition as optimal probabilistic inference, Bayesian reverse-engineers apply numerous tweaks and heuristics to formulate testable hypotheses at the algorithmic and implementational levels. In so doing, they exploit recent technological advances in Bayesian artificial intelligence, machine learning, and statistics, but also consider established principles from cognitive psychology and neuroscience. Although these tweaks and heuristics are highly pragmatic in character and (...) are often deployed unsystematically, Bayesian reverse-engineering avoids several important worries that have been raised about the explanatory credentials of Bayesian cognitive science: the worry that the lower levels of analysis are being ignored altogether; the challenge that the mathematical models being developed are unfalsifiable; and the charge that the terms ‘optimal’ and ‘rational’ have lost their customary normative force. But while Bayesian reverse-engineering is therefore a viable and productive research strategy, it is also no fool-proof recipe for explanatory success. (shrink)

Clearly, if a man holds a self-contradictory belief, then his belief cannot be rational, for there can be no set of evidence sufficient to justify it. This is most apparent when the self contradictory belief is a belief in a conjunction, , rather than when it is a non-conjunctive self-contradictory belief, e.g. a belief that red is not a color.