Benedict de Spinoza, THE ETHICS
Page: 42

affirmation belongs to the essence of the idea of a triangle,
and is nothing besides. What we have said of this volition
(inasmuch as we have selected it at random) may be said of any
other volition, namely, that it is nothing but an idea. Q.E.D.

<<<<
>>>>>Proof--Will and understanding are nothing beyond the
individual volitions and ideas (II. xlviii. and note). But a
particular volition and a particular idea are one and the same
(by the foregoing Prop.); therefore, will and understanding are
one and the same. Q.E.D.

*****Note--We have thus removed the cause which is commonly
assigned for error. For we have shown above, that falsity
consists solely in the privation of knowledge involved in ideas
which are fragmentary and confused. Wherefore, a false idea,
inasmuch as it is false, does not involve certainty. When we
say, then, that a man acquiesces in what is false, and that he
has no doubts on the subject, we do not say that he is certain,
but only that he does not doubt, or that he acquiesces in what
is false, inasmuch as there are no reasons, which should cause
his imagination to waver (see II. xliv. note). Thus, although
the man be assumed to acquiesce in what is false, we shall never
say that he is certain. For by certainty we mean something
positive (II. xliii. and note), not merely the absence of doubt.

However, in order that the foregoing proposition may be fully
explained, I will draw attention to a few additional points, and
I will furthermore answer the objections which may be advanced
against our doctrine. Lastly, in order to remove every scruple,
I have thought it worth while to point out some of the
advantages, which follow therefrom. I say "some," for they will
be better appreciated from what we shall set forth in the fifth
part.

I begin, then, with the first point, and warn my readers to make
an accurate distinction between an idea, or conception of the
mind, and the images of things which we imagine. It is further
necessary that they should distinguish between idea and words,