Common words, less precise than the terms of a scientific nomenclature, differ from them also in this, that the same word may occur in different genera.  Thus, sleep is a species of repose as above; but it is also a species of unconsciousness, with co-ordinate species swoon, hypnotic state, etc.  In fact, every word stands under as many distinct genera, at least, as there are simple or indefinable qualities to be enumerated in its definition.

Sec. 3.  Partially similar to a scientific nomenclature, ordinary language has likewise a terminology for describing things according to their qualities and structure.  Such is the function of all the names of colours, sounds, tastes, contrasts of temperature, of hardness, of pleasantness; in short, of all descriptive adjectives, and all names for the parts and processes of things.  Any word connoting a quality may be used to describe many very different things, as long as they agree in that quality.

But the quality connoted by a word, and treated as always the same quality, is often only analogically the same.  We speak of a great storm, a great man, a great book; but great is in each case not only relative, implying small, and leaving open the possibility that what we call great is still smaller than something else of its kind, but it is also predicated with reference to some quality or qualities, which may be very different in the several cases of its application.  If the book is prized for wisdom, or for imagination, its greatness lies in that quality; if the man is distinguished for influence, or for courage, his greatness is of that nature; if the storm is remarkable for violence, or for duration, its greatness depends on that fact.  The word great, therefore, is not used for these things in the same sense, but only analogically and elliptically.  Similarly with good, pure, free, strong, rich, and so on.  ‘Rest’ has not the same meaning in respect of a stone and of an animal, nor ‘strong’ in respect of thought and muscle, nor ‘sweet’ in respect of sugar and music.  But here we come to the border between literal and figurative use; every one sees that figurative epithets are analogical; but by custom any figurative use may become literal.

Again, many general names of widely different meaning, are brought together in describing any concrete object, as an animal, or a landscape, or in defining any specific term.  This is the sense of the doctrine, that any concrete thing is a conflux of generalities or universals:  it may at least be considered in this way; though it seems more natural to say, that an object presents these different aspects to a spectator, who, fully to comprehend it, must classify it in every aspect.

Sec. 4.  The process of seeking a definition may be guided by the following maxims: 

(1) Find the usage of good modern authors; that is (as they rarely define a word explicitly), consider what in various relations they use it to denote; from which uses its connotation may be collected.