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F.R.L. First Rule of Logic

1.135-140      G-c.1899-1

  135. Upon this first, and in one sense this sole, rule of
reason, that in order to learn you must desire to learn, and in
so desiring not be satisfied with what you already incline to
think, there follows one corollary which itself deserves to be
inscribed upon every wall of the city of philosophy:
Do not block the way of inquiry.
  13t;. Although it is better to be methodical in our
investigations, and to consider the economics of research, yet there is
no positive sin against logic in trying any theory which may
come into our heads, so long as it is adopted in such a sense
as to permit the investigation to go on unimpeded and
undiscouraged. On the other hand, to set up a philosophy which
barricades the road of further advance toward the truth is the
one unpardonable offence in reasoning, as it is also the one to
which metaphysicians have in all ages shown themselves the
most addicted.
  Let me call your attention to four familiar shapes in which
this venomous error assails our knowledge:

  * From unpaginated ms. "F. R. L.," c. 1899.

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  137. The first is the shape of absolute assertion. That
we can be sure of nothing in science is an ancient truth. The
Academy taught it. Yet science has been infested with
overconfident assertion, especially on the part of the third-rate and
fourth-rate men, who have been more concerned with teaching
than with learning, at all times. No doubt some of the
geometries still teach as a self-evident truth the proposition that if
two straight lines in one plane meet a third straight line so as
to make the sum of the internal angles on one side less than
two right angles those two lines will meet on that side if
sufficiently prolonged. Euclid, whose logic was more careful, only
reckoned this proposition as a Postulate, or arbitrary
Hypothesis. Yet even he places among his axioms the proposition that
a part is less than its whole, and falls into several conflicts with
our most modern geometry in consequence. But why need we
stop to consider cases where some subtilty of thought is
required to see that the assertion is not warranted when every
book which applies philosophy to the conduct of life lays down
as positive certainty propositions which it is quite as easy to
doubt as to believe?
  138. The second bar which philosophers often set up across
the roadway of inquiry lies in maintaining that this, that, and
the other never can be known. When Auguste Comte was
pressed to specify any matter of positive fact to the knowledge
of which no man could by any possibility attain, he instanced
the knowledge of the chemical composition of the fixed stars;
and you may see his answer set down in the Philosophie
positive.* But the ink was scarcely dry upon the printed page before
the spectroscope was discovered and that which he had deemed
absolutely unknowable was well on the way of getting
ascertained. It is easy enough to mention a question the answer to
which is not known to me today. But to aver that that answer
will not be known tomorrow is somewhat risky; for oftentimes
it is precisely the least expected truth which is turned up under
the ploughshare of research. And when it comes to positive
assertion that the truth never will be found out, that, in the
light of the history of our time, seems to me more hazardous
than the venture of Andr�e. **

  * 19me le�on.
  ** In 1897 Salomon August Andree attempted to fly over the polar regions
in a balloon. He died in the attempt.
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  139. The third philosophical stratagem for cutting off
inquiry consists in maintaining that this, that, or the other
element of science is basic, ultimate, independent of aught else,
and utterly inexplicable -- not so much from any defect in our
knowing as because there is nothing beneath it to know. The
only type of reasoning by which such a conclusion could
possibly be reached is retroduction. Now nothing justifies a
retroductive inference except its affording an explanation of the
facts. It is, however, no explanation at all of a fact to
pronounce it inexplicable. That, therefore, is a conclusion which
no reasoning can ever justify or excuse.
  140. The last philosophical obstade to the advance of
knowledge which I intend to mention is the holding that this or
that law or truth has found its last and perfect formulation -- 
and especially that the ordinary and usual course of nature
never can be broken through. " Stones do not fall from
heaven," said Laplace, although they had been falling upon
inhabited ground every day from the earliest times. But there
is no kind of inference which can lend the slightest probability
to any such absolute denial of an unusual phenomenon.