t differ from the manner in which a savage
wields his club. The primary power is the same in each case, and
perhaps the untutored savage has the more brawny arm of the two.
The _real_ advantage lies in the point and polish of the swordsman's
weapon; in the trained eye quick to spy out the weakness of the
adversary; in the ready hand prompt to follow it on the instant.
But, after all, the sword exercise is only the hewing and poking of the
clubman refined and developed.

So, the vast results obtained by science are won by ... no mental
processes, other than those which are practiced by everyone of us,
in the humblest and meanest affairs of life. A detective policeman
discovers a burglar from the marks made by his shoe, by a mental
process identical with that by which Cuvier restored the extinct animals
of Montmartre from fragments of their bones.... Nor does
that process of induction and deduction by which a lady finding a
stain of a peculiar kind upon her dress, concludes that somebody has
upset the inkstand thereon, differ, in any way, in kind, from that by
which Adams and Leverrier discovered a new planet.

The man of science, in fact, simply uses with scrupulous exactness
the methods which we all, habitually and at every moment, use
carelessly; and the man of business must as much avail himself of
the scientific method--must as truly be a man of science--as the
veriest bookworm of us all.[1]

[Footnote 1: Huxley: _Lay Sermons, Addresses, and Reviews_,
pp. 77, 78 (in "The Educational Value of the Natural History Sciences").]

The scientific procedure becomes, as we shall see, highly
complicated, involving elaborate processes of observation,
classification, generalization, deduction or development of
ideas, and testing. But it remains thinking just the same,
and originates in some problem or perplexity, just as thinking
does in ordinary life.

SCIENCE AND COMMON SENSE. It is profitable to note in
some detail the ways in which scientific method, in spirit and
technique, differs from common-sense thinking. It is more
insistent in the first place on including the whole range of
relevant data, of bringing to light all the facts that bear on a
given problem. In common-sense thinking we make, as we
say, snap judgments; we jump at conclusions. Anything
plausible is accepted as evidence; anything heard or seen is
accepted as a fact. The scientific examiner insists on examining
and subjecting to scrutiny the facts at ha