Epistemology: An Introduction to the Theory of Knowledge

1. Modes of Knowledge

3 Chapter 1 Modes of Knowledge SYNOPSIS • The traditional idea that knowledge is true justified belief requires both clarification and qualification. • Propositional knowledge is subject to various distinctions, among which that between explicit and inferential knowledge and that between occurrent and dispositional knowledge are particularly prominent. • When “knowledge” is construed as inferentially accessible knowledge, it becomes possible to construct what can plausibly be seen as a “logic” of knowledge. IS KNOWLEDGE TRUE JUSTIFIED BELIEF? It is something of an oversimplification to say the knowledge involves belief. For one thing, believing is sometimes contrasted with knowing as a somewhat weaker cousin. (“I don’t just believe that, I know it.”) And there are other contrast locutions as well. (“I know we won the lottery, but still can’t quite get myself to believe it.”) Still in one of the prime senses of belief—that of acceptance, of commitment to the idea that something or other is so—the knowledge of matters of fact does require an acceptance that is either actual and overt or at least a matter of tacit implicit commitment to accept. Various epistemologists have sought to characterize knowledge as true justified belief.1 In his widely discussed 1963 article, Edmund Gettier followed up on suggestions of Bertrand Russell by offering two sorts of counterexamples against this view of knowledge as consisting of beliefs that are both true and justified. Counterexample 1 Let it be that: 1. X believes p 2. p is true 3. X has justification for believing p, for example, because it follows logically from something—say q—that he also believes , although in fact 4. q is false. Here X clearly has justification for believing p, since by hypothesis thus follows logically from something that he believes. Accordingly, p is a true, justified belief. Nevertheless, we would certainly not want to say that X knows that p, seeing that his (only) grounds for believing it are false. To concretize this schematic situation let it be that: 1. X believes that Smith is in London (which is false since Smith is actually in Manchester). 2. Smith’s being in London entails that Smith is in England (which conclusion is indeed true since Smith is in Manchester). 3. X believes that Smith is in England (because he believes him to be in London). That Smith is in England is accordingly a belief of X ’s that is both true and for which X has justification. Nevertheless we would clearly not want to say that X knows that Smith is in England, since his (only) reason for accepting this is something quite false. The lesson that emerges here is that knowledge is not simply a matter of having a true belief that is somehow justified, but rather that knowledge calls for having a true belief that is appropriately justified. For the problem that the counterexample clearly indicates is that in this case the grounds that lead the individuals to adopt the belief just do not suffice to assure that which is believed . Its derivation from a false belief is emphatically not an appropriate justification for a belief. Counterexample 2 Let it be that: 1. X believes p-or-q. 2. q is true (and consequently p-or-q is also true). 4 Knowledge and Its Problems 3. X disbelieves q. 4. X believes p-or-q, but does so (only) because he believes p. 5. p is false. Here p-or-q is true. And X has justification for believing p-or-q since it follows from p which he believes. And since p-or-q is true—albeit in virtue of q’s being true (when X actually disbelieves)—it follows that p-or-q is a true, justified belief of X’s. Nevertheless, in the circumstances we would certainly not say that X knows that p-or-q, seeing that his sole grounds for believing it is once more something that is false. The difficulty here is that X holds the belief p-or-q which is justified for X because it follows from X ’s (false) belief that p, but is true just because q is true (which X altogether rejects). To concretize this situation let it be that: 1. X believes that Jefferson succeeded America’s first president, George Washington, as president 2. X accordingly believes that Jefferson or Adams was the second American president, although he thinks that Adams was the...