nd, on searching
for further facts, and on distinguishing the facts genuinely
significant in a given situation from these that happen to be
glaring or conspicuous. This is merely another way of saying
that both accuracy and completeness of observation are
demanded, accuracy in the examination of the facts present,
and completeness in the array of facts bearing on the question
at hand.

Scientific thinking is thus primarily inquiring and skeptical.
It queries the usual; it tries, as we say, to penetrate beneath
the surface. Common sense, for example, gives suction as the
explanation of water rising in a pump. But where, as at a great
height above sea level, this mysterious power of suction does
not operate, or when it is found that it does not raise water
above thirty-two feet, common sense is at a loss. Scientific
thinking tries to analyze the gross fact, and by accurately and
completely observing all the facts bearing on the phenomenon
endeavors to find out "what _special_ conditions are present
when the effect occurs" and absent when it does not occur.
Instead of trying to fit all unusual, contradictory, or exceptional
facts into _a priori_ ideas based on miscellaneous and
unsifted facts, it starts without any _fixed_ conclusions beforehand,
but carefully observes all the facts which it can secure
with reference to a particular problem, deliberately seeking
the exceptional and unusual as crucial instances. Thus in a
sociological inquiry, the scientist, instead of accepting
"common-sense" judgments (based on a variety of miscellaneous,
incomplete, and unsifted facts) that certain races are inferior
or superior, tries, by specific inquiries, to establish the facts
of racial capacities or defects. Instead of accepting proverbial
wisdom and popular estimates of the relative capacities
of men and women, he tries by careful observation and
experiment accurately to discover all the facts bearing on
the question, and to generalize from those facts.

Scientific method thus discounts prejudice or dogmatism.
A prejudice is literally a pre-judgment. Common sense sizes
up the situation beforehand. Instead of examining a situation
in its own terms, and _arriving_ at a conclusion, it _starts_
with one. The so-called hard-headed man of common sense
_knows_ beforehand. He has a definite and stereotyped reaction
for every situation with which he comes in contact.
These rubber-stamp responses, these unconsidered generalizations,