ABSTRACT

This chapter explains the modal theories of knowledge and warranted beliefs. It presents a brief exposition of Fred Dretske version of a modal theory of knowledge. Dretske points out, his theory steers clear of the drawbacks inherent in such modal theories of knowledge as reliability theories and causal theories—the major modal theories developed in response to the Gettier challenge. Dretske, in his influential papers 'Epistemic Operators' and 'Conclusive Reasons,' took the first steps in pioneering a modal theory of knowledge and justified beliefs; an approach which is now known as 'tracking theory'. By contrast, Robert Nozick's discussion takes its starting point in the observation that there has to be a modal aspect to knowledge, that knowledge requires a sensitivity of one's beliefs to truth over a range of relevant hypothetical scenarios, or possible worlds. In Nozick's terminology, the maundering brain in a vat and the intellectualising brain in a skull are employing the same method.