The question as to what we mean by truth and falsehood, which we considered in
the proceeding chapter, is of much less interest than the question as to how we can
know what is true and what is false. This question will occupy us in the present
chapter. There can be no doubt that some of our beliefs are eroneous; thus we are
led to inquire what certainty we can ever have that such and such a belief is not
erroneous. In other words, can we ever know anything at all, or do we merely
sometimes by good luck believe what is true? Before we can attack this question,
we must, however, first decide what we mean by 'knowing', and this question is not
so easy as might be supposed.
At first site we might imagine that knowledge could be defined as 'true belief'.
When what we believe is true, it might be supposed that we had achieved a
knowledge of what we believe. But this would not accord with the way in which
the word is commonly used. To take a very trivial instance: If a man believes that
the late Prime Minister's last name began with a B, he believes what is true, since
the late Prime Minister was Sir Henry Campbell Bannerman. But if he believes
that Mr. Balfor was the late Prime Minister, he will still believe that the late Prime
Minister's last name began with a B, yet this belief, though true, would not be
thought to constitute knowledge. If a newspaper, by an intelligent anticipation,
announces the result of a battle before any telegram giving the result has been
received, it may by good fortune announce what afterwards turns out to be the right
result, and it may produce belief in some of its less experienced readers.