Truth Value (working assumptions): Truth-or-falsity. In our logic, there are just two truth values: true and false. A proposition is true if it corresponds to reality; otherwise it is false. We make, and will defend, the following two controversial claims about truth value: (1) Truth (and falsity) for our purposes do not admit of degree. (2) Truth (and falsity) are "absolute" in the sense that they are not relative to persons, times, places or cultures. Now this represents a simplification or "idealization” of the way in which notions like truth and falsity figure in our ordinary ways of thinking, however we shall argue that, for most purposes, this does not represent a significant loss, particularly if we are careful to distinguish semantic notions, concepts which concern the way in which language connects to the world like truth, falsity and meaning, from epistemic notions, like belief and justification, concepts which pertain to people’s knowledge or beliefs about the world.

Propositional Attitudes are ways in which people (and other intelligent beings) are related to propositions, thus, for example, belief is a propositional attitude.
Beliefs are characterized as "true" or "false" in virtue of the truth or falsity of the propositions that are believed. People can believe propositions with varying degrees of conviction, but believing something does not make it so, no matter how hard you believe. Furthermore, the truth (or falsity) of a proposition isn't determined by how many people believe it or by who believes it. Finally, some propositions are controversial: they are believed by some with good reason, and disbelieved by others with good reason, and it may never be possible to find out conclusively who's right. It does not however follow that such propositions are neither true nor false. There are right answers, even if we are not and never will be in a position to determine what they are.

(Epistemic) Justification: Some beliefs are epistemically justified, that is, people who believe them have good reason to believe them. One can be justified in believing something that is true or one can be justified in believing something that is false. For much of what we believe however, both truly and falsely, we do not have any good reasons: we make guesses, both lucky and unlucky, we take things on faith, and so on. There's nothing wrong with this, in fact, ironically, there may be compelling reasons to believe things for which we don't have epistemic justification and for taking certain things on faith. It is important however to be clear about the distinction between the truth-or-falsity of a belief on the one hand and the justification a person may have for believing it on the other. Notice that, unlike the truth (or falsity) of a belief, the justification of a belief is relative to persons in the sense that one person may be justified in believing a certain proposition while another person may believe the same thing without justification. Moreover, people may hold beliefs for different reasons and with different degrees of conviction.

Knowledge traditionally has been understood as "justified true belief.”

Questions to Think About

1.  Do you think that some propositions are somewhere in between true and false? If so, think of some examples and explain why you don't want to say that they're absolutely true or absolutely false.

2.   Do you think that some propositions are true for some people but not for others? If so, think of some examples and explain why you want to say that "what's true for one person may not be true for another."

3.  Given the above account of truth and justification, can there be unjustified true beliefs? If so, think of examples and explain. If not, why not?

4.  Given the above account of truth and justification, can there be justified false beliefs? If so, think of examples and explain. If not, why not?