ABSTRACT
The fundamental doctrine of externalism is that what must be added to true belief to obtain knowledge is the appropriate connection between belief and truth. The central tenet of externalism is that some relationship to the external world accounting for the truth of our belief suffices to convert true belief to knowledge without our having any idea of that relationship. Before turning to details and objections, the authors note the advantages of externalism. First, according to some externalists, the need for justification and a theory of justification is eliminated as a component of an analysis of knowledge. Moreover, it is easy to see that externalism in no way requires such a restrictive conception of the external relationship. The general opacity problem for externalism can be seen most graphically by considering an analogy proposed by Armstrong. He suggested that the right model of knowledge is a thermometer.
