ve us
information. Our knowledge of these intellectual forms is, however,
founded upon "beliefs" rather than upon immediate intuition, and the
objective certainty of science, upon the subjective necessity of
believing, and not upon direct apperception.

[Footnote 688: "On the Soul," ch. vi.; "Ethics," bk. vi. ch. i.]

[Footnote 689: "Metaphysics," bk. vi. ch. xiii.]

[Footnote 690: Ibid., bk. vii. ch. iii.]

The points of contrast between the two methods may now be presented in a
few sentences. Plato held that all our cognitions are reducible to two
elements--one derived from _sense_, the other from _pure reason_; one
element particular, contingent, and relative, the other universal,
necessary, and absolute. By an act of _immediate abstraction_ Plato will
eliminate the particular, contingent, and relative phenomena, and
disengage the universal, necessary, and absolute _ideas_ which underlie
and determine all phenomena. These ideas are the thoughts of the Divine
Mind, according to which all particular and individual existences are
generated, and, as divine thoughts, they are real and permanent
existences. Thus by a process of immediate abstraction, he will rise
from particular and contingent phenomena to universal and necessary
principles, and from these to the First Principle of all principles, the
First Cause of all causes--that is, to _God_.

Aristotle, on the contrary, held that all of our knowledge begins with
"the singular," that is, with the particular and the relative, and is
derived from sensation and experience. The "sensible object," taken as
it is without any sifting and probing, is the basis of science, and
reason is simply the architect constructing science according to certain
"forms" or laws inherent in mind. The object, then, of metaphysical
science is to investigate those "universal notions" under which the mind
conceives of and represents to itself external objects, and speculates
concerning them. Aristotle, therefore, agrees with Plato in teaching
"that science can only be a science of universals,"[691] and "that
sensation alone can not furnish us with scientific knowledge."[692] How,
then, does he propose to attain the knowledge of universal principles?
How will he perform that feat which he calls "passing from the known to
the unknown?" The answer is, by _comparative abstraction_. The universal
being constituted by a relation of the object to the thinking subject,
that is, by a property recogni