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 is
meant by saying that they have developed a philosophy about these matters.
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 man's firmest beliefs are dubious
or possibly even chimerical. Such doubts and hesitations are caused
by anomalous features of the world that most people notice but tend to
minimize or ignore. Epistemologists notice these things too, but, in wondering
about them, they come to realize 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
such anomalies and perplexities, which will be discussed below in the section
on the history of epistemology, 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.