ays these names begin as figures of
speech, but where they are used accurately they have a perfectly exact
meaning. Darwin has given some account of this process of language:

"It has been said that I speak of natural selection as an active power
or deity, but who objects to an author speaking of the attraction of
gravity as ruling the movements of planets? Every one knows what is
meant by such metaphorical expressions, and they are almost necessary
for brevity: so, again, it is difficult to avoid personifying the word
'Nature.' But I mean by Nature the aggregate action and product of many
laws, and by laws the sequence of events as ascertained by us."[30]

When the facts intended to be meant by a phrase are thus carefully
specified and delimited, the phrase ceases to be a figure of speech, and
becomes the name of a class or of a principle.

Generalization and classification always take place for purposes of
reasoning;[31] and reasoning which is dependent on them rests on the
assumption that things are uniformly correlated in nature; when we
throw things together into classes we assume that what is true for one
member of a class, so far as it is a member of that class, is true to
the same extent and for the purpose for which the class is made for all
other members of that class.

In practice a large part of our reasoning is through generalization and
classification; and as we have seen, it has a more substantial basis
than when we rest on an analogy. If you hear that your brother has been
elected to the Phi Beta Kappa, you reason from the generalization that
all members of the Phi Beta Kappa are high scholars to the inference
that your brother must have taken high rank. When I see a gang of
carpenters knocking off work at four o'clock in the afternoon, I infer
that they must belong to the union, because I know that unions as a
class have established an eight-hour day. If you were arguing that the
standards for graduation from your college should be raised, you would
try to show that each year enough men are graduated with low
intellectual attainments to make a class large enough to generalize
from. If you were arguing that your city should establish a municipal
gymnasium, you would try to show that of the boys and young men brought
before the police courts for petty mischief and more serious offenses
almost all have lacked the chance to work off their animal spirits in a
healthy way. Wherever you can thus establish y