le to hinder us from understanding.

Proof.--The mind, in so far as it reasons, desires nothing
beyond understanding, and judges nothing to be useful to itself,
save such things as conduce to understanding (by the foregoing
Prop.). But the mind (II. xli., xliii. and note) cannot possess
certainty concerning anything, except in so far as it has
adequate ideas, or (what by II. xl. note, is the same thing) in
so far as it reasons. Therefore we know nothing to be good or
evil save such things as really conduce, &c. Q.E.D.

PROP. XXVIII. The mind's highest good is the knowledge of God,
and the mind's highest virtue is to know God.

Proof.--The mind is not capable of understanding anything
higher than God, that is (I. Def. vi.), than a Being absolutely
infinite, and without which (I. xv.) nothing can either be or be
conceived; therefore (IV. xxvi. and xxvii.), the mind's highest
utility or (IV. Def. i.) good is the knowledge of God. Again,
the mind is active, only in so far as it understands, and only to
the same extent can it be said absolutely to act virtuously. The
mind's absolute virtue is therefore to understand. Now, as we
have already shown, the highest that the mind can understand is
God; therefore the highest virtue of the mind is to understand
or to know God. Q.E.D.

PROP. XXIX. No individual thing, which is entirely different
from our own nature, can help or check our power of activity, and
absolutely nothing can do us good or harm, unless it has
something in common with our nature.

Proof.--The power of every individual thing, and consequently
the power of man, whereby he exists and operates, can only be
determined by an individual thing (I. xxviii.), whose nature (II.
vi.) must be understood through the same nature as that, through
which human nature is conceived. Therefore our power of
activity, however it be conceived, can be determined and
consequently helped or hindered by the power of any other
individual thing, which has something in common with us, but not
by the power of anything, of which the nature is entirely
different from our own; and since we call good or evil that
which is the cause of pleasure or pain (IV. viii.), that is (III.
xi. note), which increases or diminishes, helps or hinders, our
power of activity; therefore, that which is entirely different
from our nature can neither be to us good nor bad. Q.E.D.

PROP. XXX. A thing cannot be bad for us through the quality
which