_Every whole is greater than its part_; and, _Things which are equal
to the same thing are equal to one another_. Some propositions again
are self-evident only to the wise, who understand the meaning of the
terms: as, to one who understands that an angel is not a body, it is
self-evident that an angel is not in a place by way of
circumscription; [Footnote 11] which is not manifest to others, who do
not understand the term." (St. Thos., 1a 2a q. 94, art. 2, in corp.)

[Footnote 11: _Circumscriptive_, which word is explained by St. Thos.,
1a, q. 52. art. 1.]

One more extract. "From the very nature of an intellectual soul it is
proper to man that, as soon as he knows what a whole is, and what a
part is, he knows that every whole is greater than its part; and so of
the rest. But what is a whole, and what a part, that he cannot know
except through sensory impressions. And therefore Aristotle shows that
the knowledge of principles comes to us through the senses." (St.
Thos., 1a 2a, q. 51, art. 1, in corp.)

7. Thus the propositions that _right is to be done, benefactors to be
requited_, are self-evident, necessary truths, to any child who has
learned by experience the meaning of _right_, of _kindness_, and of a
_return of kindness._ "Yes, but"--some one will say--"how ever does he
get to know what _right_ and _wrong_ are? Surely sensory experience
cannot teach him that." We answer, man's thoughts begin in sense, and
are perfected by reflection. Let us take the idea of _wrong_, the key
to all other elementary moral ideas. The steps by which a child comes
to the fulness of the idea of _wrong_ may be these. First, the thing
is _forbidden_: then one gets _punished_ for it. Punishment and
prohibition enter in by eye and ear and other senses besides. Then the