nite relative modes.
These categories are so related that each involves the existence of
one higher than itself, thus there cannot be a [Greek: pros ti pos
echon] which does not rest upon or imply a [Greek: pos echon], but
[Greek: pos echon] is impossible without [Greek: poion], which only
exists in [Greek: hypokeimenon], a form or phase of [Greek: to
hon].[8]

Plotinus, after a lengthy critique of Aristotle's categories, sets out
a twofold list. [Greek: to en, kinesis, stasis, tautotes, heterotes]
are the primitive categories ([Greek: prota gene]) of the intelligible
sphere. [Greek: ousia, pros ti, poia, poson, kinesis] are the
categories of the sensible world. The return to the Platonic
classification will not escape notice.

Modern philosophy.

Modern philosophy, neglecting altogether the dry and tasteless
treatment of the Aristotelian doctrine by scholastic writers, gave a
new, a wider and deeper meaning to the categories. They now appear as
ultimate or root notions, the metaphysical or thought elements, which
give coherence and consistency to the material of knowledge, the
necessary and universal relations which obtain among the particulars
of experience. There was thus to some extent a return to Platonism,
but in reality, as might easily be shown, the new interpretation was,
with due allowance for difference in point of view, in strict harmony
with the true doctrine of Aristotle. The modern theory dates in
particular from the time of Kant, who may be said to have reintroduced
the term into philosophy. Naturally there are some anticipations in
earlier thinkers. The Substance, Attribute and Mode of Cartesianism
can hardly be classed among the categories; nor does Leibnitz's chance
suggestion of a fivefold arrangement into Substance, Quantity,
Quality, Action and Passion, and Relations, demand any particular
notice. Locke, too, has a classification into Substances, Modes and
Relations, but in it he has manifestly no intention of drawing up a
table of categories. What in his system corresponds most nearly to the
modern view of these elements is the division of kinds of real
predication. In all judgments of knowledge we predicate either (1)
Identity or Diversity, (2) Relation, (3) Co-existence, or necessary
connexion, or (4) Real existence. From this the transition was easy to
Hume's important classification of _philosophical relations_ in