C. S. Peirce, excerpts from Ms. 692:
Now our percepts and direct observations relate exclusively to the
circumstances that happened to exist when they were made, and not to any
future occasion in which we might be in doubt how to act. Consequently,
observed facts do not, in themselves, contain any practical knowledge;
and in order to attain such knowledge, additions must be made to the
data of perception. Any proposition added to the percepts, tending to
make those data illuminate other circumstances than those under which
they were observed, may be called a hypothesis. For instance, it is a
hypothesis that thirteen of the present United States were former
colonies of Great Britain. For it cannot be directly observed. All that
we can observe is that it is so asserted in books and tradition, and
that a few monuments of divers kinds support the assertion. [pg. 13-14]
That neither deduction nor induction can ever add the smallest item to
the data of perception; and, as we have already noticed, mere percepts
do not constitute any knowledge applicable to any practical or
theoretical use. All that makes knowledge applicable comes to us via
abduction. Looking out my window this lovely spring morning I see an
azalea in full bloom. No, no! I do not see that; though that is the only
way I can describe what I see. That is a proposition, a sentence, a
fact; but what I perceive is not proposition, sentence, fact, but only
an image, which I make intelligible in part by means of a statement of
fact. This statement is abstract; but what I see is concrete. I perform
an abduction when I so much as express in a sentence anything I see. The
truth is that the whole fabric of our knowledge is one matted felt of
pure hypothesis confirmed and refined by induction. Not the smallest
advance can be made in knowledge beyond the stage of vacant staring,
without making an abduction at every step. [pg. 26-27]
