Categories

Categories, or Heads of Predicables (Gr. kategorein, to accuse, hence to state), the heads under which all logical terms and all objects of knowledge have been arranged by philosophers. Aristotle considered knowledge and existence under the heads of Being, Quantity, Quality, Relation, Place, Time, Position, State or Condition (habitus), Action, Passion. These heads have been much discussed, criticised, and modified. The Stoics considered Being under the heads of substance, quality, and relation. Trendelenburg, who looked upon Aristotle's categories as in some measure corresponding with the parts of speech, considered Being as motion under the conditions of time and space and as divisible under what he called mathematical and real categories. Kant's categories (twelve in number) are the leading types of concept implied in the judgments of which all our knowledge consists - including unity and plurality, substance and cause, etc. - the forms of thought without which knowledge could not subsist: while Hegel's are the concepts successively posted by Absolute Thought in the construction of the Universe, and also by human thought in the history of the race and the individual. J. S. Mill classed possible knowledge quite differently from Aristotle, and in a way hardly consistent with his own Idealism. He makes four classes: (1) States of consciousness or feelings; (2) the mind which feels; (3) external objects which excite feelings; (4) relations between feelings. Spencer (First Principles) points out how reasoning often consists in bringing phenomena under an ever-widening circle of other phenomena.