ASSURANCE PRINCIPLE

Assurance Principle

Assurance Principle

This essay concerns the speech act of testimony, one of the most common acts we perform. When we tell a passing stranger the time, and when we tell our friends how our work is going, our speech communicates information that our hearers would not have but for that speech. Much of our knowledge is attained through testimony, spoken or written. For instance, we would know almost nothing about history if it were not for the accounts of witnesses and historians. This raises the question: What kind of reason do we have to believe what we are told?

Testimony is not only a source of knowledge, but also a voluntary act of the teller's. The teller can choose her words, and she can choose whether to tell the truth or to say what she believes to be false. As such, she can be held responsible for her testimony. She may have certain obligations that she should fulfill in her testimony, as she does in carrying out any other act. [1]

This essay will give a unified treatment of the epistemology of testimony and of its normative structure. As we will see, a satisfactory account of the epistemology of testimony must allow for the fact that testimony is a voluntary act for which the teller assumes responsibility. Some of the norms on testimony, in turn, can be deduced from the epistemology of testimony. The teller assumes responsibility her testimony because she stakes her credibility on its truth. Testimony's dual nature, as a source of knowledge and as an act on which there are norms, is no accident; each of these aspects is necessary for the other.

1. The Epistemological Problem

The most obvious questions about testimony are epistemological. Given that we learn so much from other people, we might ask how it is that we can learn from the testimony of others. Are we ever justified in believing what someone tells us, just because she has told us? If so, when, and how? These questions are important for the study of knowledge, and central to the study of testimony. Communicating knowledge and inducing beliefs are among the essential functions, if testimony has essential functions at all. The question is, when does testimony justify the hearer in believing what she is told, and how?

One strand of modern philosophy argues that we should not accept testimony, or at least that acceptance of testimony does not yield knowledge. Another strand of philosophy holds that we are often justified in believing what we are told, but that justification arises from principles of justification that give no special status to testimony. Still another view is that our reliance on testimony is justified, and that this justification is specific to testimony and cannot be reduced to non-testimonial forms of justification. [1]

This essay argues that there is a special kind of justification for our reliance on testimony that is irreducible to non-testimonial forms of justification, but that this justification is severely ...