Benedict de Spinoza, THE ETHICS
Page: 29

the privation of knowledge, which inadequate, fragmentary, or
confused ideas involve. Q.E.D.

*****Note--In the note to II. xvii. I explained how error
consists in the privation of knowledge, but in order to throw
more light on the subject I will give an example. For instance,
men are mistaken in thinking themselves free; their opinion is
made up of consciousness of their own actions, and ignorance of
the causes by which they are conditioned. Their idea of
freedom, therefore, is simply their ignorance of any cause for
their actions. As for their saying that human actions depend on
the will, this is a mere phrase without any idea to correspond
thereto. What the will is, and how it moves the body, they none
of them know; those who boast of such knowledge, and feign
dwellings and habitations for the soul, are wont to provoke
either laughter or disgust. So, again, when we look at the sun,
we imagine that it is distant from us about two hundred feet;
this error does not lie solely in this fancy, but in the fact
that, while we thus imagine, we do not know the sun's true
distance or the cause of the fancy. For although we afterwards
learn, that the sun is distant from us more than six hundred of
the earth's diameters, we none the less shall fancy it to be
near; for we do not imagine the sun as near us, because we are
ignorant of its true distance, but because the modification of
our body involves the essence of the sun, in so far as our said
body is affected thereby.

XXXVI. Inadequate and confused ideas follow by the same
necessity, as adequate or clear and distinct ideas.

>>>>>Proof--All ideas are in God (I. xv.), and in so far as they
are referred to God are true (II. xxxii.) and (II. vii. Cor.)
adequate; therefore there are no ideas confused or inadequate,
except in respect to a particular mind (cf. II. xxiv. and
xxviii.); therefore all ideas, whether adequate or inadequate,
follow by the same necessity (II. vi.). Q.E.D.

XXXVII. That which is common to all (cf. Lemma II, above), and
which is equally in a part and in the whole, does not constitute
the essence of any particular thing.