If, however, the predicaments are heads of a classification of terms predicable, we may expect to find some connection with the predicables; and, in fact, secondary Substances are species and genus; whilst the remaining nine forms are generally accidents.  But, again, we may expect some agreement between them and the fundamental forms of predication (ante, chap. i.  Sec. 5, and chap. ii Sec. 4):  Substance, whether as the foundation of attributes, or as genus and species, implies the predication of co-inherence, which is one mode of Co-existence.  Quantity is predicated as equality (or inequality) a mode of Likeness; and the other mode of Likeness is involved in the predication of Quality.  Relation, indeed, is the abstract of all predication, and ought not to appear in a list along with special forms of itself.  ‘Where’ is position, or Co-existence in space; and ‘When’ is position in time, or Succession.  Action and Passion are the most interesting aspect of Causation.  Posture and Habit are complex modes of Co-existence, but too specialised to have any philosophic value.  Now, I do not pretend that this is what Aristotle meant and was trying to say:  but if Likeness, Co-existence, Succession and Causation are fundamental forms of predication, a good mind analysing the fact of predication is likely to happen upon them in one set of words or another.

By Kant the word ‘Category’ has been appropriated to the highest forms of judgment, such as Unity, Reality, Substance, and Cause, under which the understanding reduces phenomena to order and thereby constitutes Nature.  This change of meaning has not been made without a certain continuity of thought; for forms of judgment are modes of predication.  But besides altering the lists of categories and greatly improving it, Kant has brought forward under an old title a doctrine so original and suggestive that it has extensively influenced the subsequent history of Philosophy.  At the same time, and probably as a result of the vogue of the Kantian philosophy, the word ‘category’ has been vulgarised as a synonym for ‘class,’ just as ‘predicament’ long ago passed from Scholastic Logic into common use as a synonym for ‘plight.’  A minister is said to be ‘in a predicament,’ or to fall under the ’category of impostors.’

CHAPTER XXIII

DEFINITION OF COMMON TERMS

Sec. 1.  Ordinary words may need definition, if in the course of exposition or argument their meaning is liable to be mistaken.  But as definition cannot give one the sense of a popular word for all occasions of its use, it is an operation of great delicacy.  Fixity of meaning in the use of single words is contrary to the genius of the common vocabulary; since each word, whilst having a certain predominant character, must be used with many shades of significance, in order to express the different thoughts and feelings of multitudes of men in endlessly diversified situations; and its force, whenever it is used, is qualified by the other words with which it is connected in a sentence, by its place in the construction of the sentence, by the emphasis, or by the pitch of its pronunciation compared with the other words.