perly, defining _not the
name but the thing_), he must select from the attributes in which the
denoted objects agree, choosing, as the common properties are always
many, and, in a _kind_, innumerable, those which are familiarly
predicated of the class, and out of them, if possible, or otherwise,
even in preference to them, the ones on which depend, or which are the
best marks of, those thus familiarly predicated. To do this
successfully, presumes a knowledge of all the common properties of the
class, and the relations between them of causation and dependence. Hence
the discussion of non-verbal definitions (which Dr. Whewell calls the
Explication of Conceptions) is part of the business of discovery. Hence,
too, disputes in science have often assumed the form of a battle of
definitions; such definitions being not arbitrary, but made with a view
to some tacitly assumed principle needing expression.

We ought, if possible, to define in consonance with the denotation. But
sometimes this is impossible, through the name having accumulated
_transitive_ applications, in its gradual extension from one object, in
relation to which it connotes one property, to another which resembles
the former, but in quite a different attribute. These _transitive_
applications, even when found to correspond in different languages, may
have arisen, not from any common quality in the objects, but from some
association of ideas founded on the common nature and condition of
mankind. When the association is so natural and habitual as to become
virtually indissoluble, the _transitive_ meanings are apt to coalesce in
one complex conception; and every new transition becomes a more
comprehensive generalisation of the term in question. In such cases the
ancients and schoolmen did not suspect, what otherwise they carefully
watched for, viz. ambiguities: not Plato, though his Comparisons and
Abstractions preparatory to Induction are perfect; not even Bacon, in
his speculations on Heat. Hence have sprung the various vain attempts to
trace a common idea in all the uses of a word, such as _Cause_
(Efficient, Material, Formal, and Final _Cause_), _the Good_, _the Fit_.

When a term is applied to many different objects agreeing _all_ only in
_one_ quality (e.g. things _beautiful_, in _agreeableness_), though
_most_ agree in something besides, it is better to exclude part of the
denotation than of the connotation, however indistinct: else language
ceases to keep