llac says, an
_analysis_. Even when a name connotes only a single attribute, it (and
also the corresponding abstract name itself) can yet be defined (in this
sense of being analysed or resolved into its elements) by declaring the
connotation of that attribute, whether, if it be a union of several
attributes (e.g. Humanity), by enumerating them, or, if only one (e.g.
Eloquence), by dissecting the fact which is its foundation. Even when
the fact which is the foundation of the attribute is a simple feeling,
and therefore incapable of analysis, still, if the simple feeling have a
name, the attribute and the object possessing it may be defined by
reference to the fact: e.g. a white object is definable as one exciting
the sensation of white; and whiteness, as the power of exciting that
sensation. The only names, abstract or concrete, incapable of analysis,
and therefore of definition, are proper names, as having no meaning, and
also the names of the simple feelings themselves, since these can be
explained only by the resemblance of the feelings to former feelings
called by the same or by an exactly synonymous name, which consequently
equally needs definition.

Though the only accurate definition is one declaring all the facts
involved in the name, i.e. its connotation, men are usually satisfied
with anything which will serve as an index to its denotation, so as to
guard them from applying it inconsistently. This was the object of
logicians when they laid down that a species must be defined _per genus
et differentiam_, meaning by the _differentia one_ attribute included in
the essence, i.e. in the connotation. And, in fact, one attribute, e.g.
in defining man, Rationality (Swift's Houyhnhms having not been as yet
discovered) often does sufficiently mark out the objects denoted. But,
besides that a definition of this kind ought, in order to be complete,
to be _per genus et differentias_, i.e. by _all_ the connoted attributes
not implied in the name of the _genus_, still, even if all were given, a
_summum genus_ could not be so defined, since it has no superior genus.
And for merely marking out the objects denoted, Description, in which
none of the connoted attributes are given, answers as well as logicians'
so-called _essential_ definition. In Description, any one or a
combination of attributes may be given, the object being to make it
exactly coextensive with the name, so as to be predicable of the same
things. Such a descript