Belief's Own Ethics

Belief's Own Ethics

By Jonathan E. Adler

A Bradford Book





The fundamental question of the ethics of belief is "What ought one to believe?" According to the traditional view of evidentialism, the strength of one's beliefs should be proportionate to the evidence. Conventional ways of defending and challenging evidentialism rely on the idea that what one ought to believe is a matter of what it is rational, prudent, ethical, or personally fulfilling to believe. Common to all these approaches is that they look outside of belief itself to determine what one ought to believe.

In this book Jonathan Adler offers a strengthened version of evidentialism, arguing that the ethics of belief should be rooted in the concept of belief—that evidentialism is belief's own ethics. A key observation is that it is not merely that one ought not, but that one cannot, believe, for example, that the number of stars is even. The "cannot" represents a conceptual barrier, not just an inability. Therefore belief in defiance of one's evidence (or evidentialism) is impossible. Adler addresses such questions as irrational beliefs, reasonableness, control over beliefs, and whether justifying beliefs requires a foundation. Although he treats the ethics of belief as a central topic in epistemology, his ideas also bear on rationality, argument and pragmatics, philosophy of religion, ethics, and social cognitive psychology.


Out of Print ISBN: 9780262011921 373 pp. | 6 in x 9 in


$23.00 X ISBN: 9780262511940 373 pp. | 6 in x 9 in


  • The best single-book treatment of the problem of the ethics of belief, in defense of a strongly evidentialist view.

    Oxford Bibliographies

  • A beautiful book that is exceptionally learned and rich.

    Igor Douven

    Ars Disputandi


  • Combining an agreeable learnedness with analytical rigor, Jonathan Adler has made an original and important contribution to the ethics-of-belief tradition in epistemology.

    John Woods

    Director, Abductive Systems Group, Department of Philosophy, University of British Columbia

  • I found Adler's comparison of belief with assertion, and his more epistemological interest in the concept of belief, original and fascinating. The book was a real eye opener to me. Whereas W.K. Clifford famously said that one ought not to believe without evidence, Adler holds that strictly speaking it is not even possible to believe without evidence.

    J.J.C. Smart

    Emeritus Professor, Australian National University

  • In this exciting and wide-ranging new book, Adler defends the position he calls 'strong evidentialism.' His inquiry weaves together many threads in a rich fabric that will be of great interest to those in informal logic and argumentation theory. Among the threads that caught my attention were a fascinating treatment of testimony, new light on the appeal to ignorance, and discussions of burden of proof and the meaning of reasonableness.

    Ralph H. Johnson

    University Professor, Department of Philosophy, University of Windsor, Canada