Epistemology as a discipline. Why should there be such a subject as epistemology Aristotle provided the answer when he said that philosophy begins in wonder, in a kind of puzzlement about things.
Nearly all human beings wish to comprehend the world they live in, a world that includes the individual as well as other persons, and most people construct hypotheses of varying degrees of sophistication to help them make sense of that world. No conjectures would be necessary if the world were simple but its features and events defy easy explanation. The ordinary person is likely to give up somewhere in the process of trying to develop a coherent account of things and to rest content with whatever degree of understanding he has managed to achieve.
Philosophers, in contrast, are struck by, even obsessed by, matters that are not immediately comprehensible. Philosophers are, of course, ordinary persons in all respects except perhaps one. They aim to construct theories about the world and its inhabitants that are consistent, synoptic, true to the facts and that possess explanatory power. They thus carry the process of inquiry further than people generally tend to do, and this is what saying that they have developed a philosophy about these matters means.
Epistemologists, in particular, are philosophers whose theories deal with puzzles about the nature, scope, and limits of human knowledge. Like ordinary persons, epistemologists usually start from the assumption that they have plenty of knowledge about the world and its multifarious features. Yet, as they reflect upon what is presumably known, epistemologists begin to discover that commonly accepted convictions are less secure than originally assumed and that many of mans firmest beliefs are dubious or possibly even chimerical.
Anomalous features of the world that most people notice but tend to minimise or ignore cause such doubts and hesitations. Epistemologists notice these things too, but, in wondering about them, they come to realise that they provide profound challenges to the knowledge claims that most individuals blithely and unreflectingly accept as true. What then are these puzzling issues While there is a vast array of anomalies and perplexities, two of these issues will be briefly described in order to illustrate why such difficulties call into question common claims to have knowledge about the world.