Apart from the development of scientific method, inferences
depend upon habits that have been built up under the influence
of a number of particular experiences not themselves arranged
for logical purposes. A says, “It will probably rain to-morrow.”
B asks, “Why do you think so?” and A replies, “Because the sky
was lowering at sunset.” When B asks, “What has that to do
with it?” A responds, “I do not know, but it generally does
rain after such a sunset.” He does not perceive any connection
between the appearance of the sky and coming rain; he is not
aware of any continuity in the facts themselves--any law or
principle, as we usually say. He simply, from frequently
recurring conjunctions of the events, has associated them so
that when he sees one he thinks of the other. One suggests the
other, or is associated with it. A man may believe it will rain
to-morrow because he has consulted the barometer; but if he
has no conception how the height of the mercury column (or the
position of an index moved by its rise and fall) is connected
with variations of atmospheric pressure, and how these in turn
are connected with the amount of moisture in the air, his belief
in the likelihood of rain is purely empirical. When men lived in
the open and got their living by hunting, fishing, or pasturing
flocks, the detection of the signs and indications of weather
changes was a matter of great importance. A body of proverbs and
maxims, forming an extensive section of traditionary folklore,
was developed. But as long as there was no understanding why or
how certain events were signs, as long as foresight and weather
shrewdness rested simply upon repeated conjunction among facts,
beliefs about the weather were thoroughly empirical.--JOHN
DEWEY, “How we Think.”
(3226)
* * * * *
While many empirical conclusions are, roughly speaking, correct;
while they are exact enough to be of great help in practical
life; while the presages of a weatherwise sailor or hunter may
be more accurate, within a certain restricted range, than those
of a scientist who relies wholly upon scientific observations
and tests; while, indeed, empirical observations and records
furnish the raw or crude material of scientific knowledge, yet
the empirical method affords no way of discriminating between
right and wrong conclusions. Hence it is responsible for a
multitude of false beliefs. The technical designation for
one of the commonest fallacies is _post hoc, ergo propter
hoc_; the belief that because one thing comes after another,
it comes because of the other. Now this fallacy of method is
the animating principle of empirical conclusions, even when
correct--the correctness being almost as much a matter of
good luck as of method. That potatoes should be planted only
during the crescent moon, that near the sea people are born
at high-tide and die at low-tide, that a comet is an omen of
danger, that bad luck follows the cracking of a mirror, that
a patent medicine cures a disease--these and a thousand like
notions are asseverated on the basis of empirical coincidence
and conjunction. Moreover, habits of expectation and belief
are formed otherwise than by a number of repeated similar
cases.--JOHN DEWEY, “How We Think.”
(3227)