to a
man, as by being changed into an insect. What I mean is, that we
conceive the thing's power of action, in so far as this is
understood by its nature, to be increased or diminished. Lastly,
by perfection in general I shall, as I have said, mean reality--in
other words, each thing's essence, in so far as it exists, and
operates in a particular manner, and without paying any regard to
its duration. For no given thing can be said to be more perfect,
because it has passed a longer time in existence. The duration
of things cannot be determined by their essence, for the essence
of things involves no fixed and definite period of existence;
but everything, whether it be more perfect or less perfect, will
always be able to persist in existence with the same force
wherewith it began to exist; wherefore, in this respect, all
things are equal.

DEFINITIONS.

I. By good I mean that which we certainly know to be useful to
us.

II. By evil I mean that which we certainly know to be a
hindrance
to us in the attainment of any good.

(Concerning these terms see the foregoing preface towards the
end.)

III. Particular things I call contingent in so far as, while
regarding their essence only, we find nothing therein, which
necessarily asserts their existence or excludes it.

IV. Particular things I call possible in so far as, while
regarding the causes whereby they must be produced, we know not,
whether such causes be determined for producing them.

(In I. xxxiii. note. i., I drew no distinction between
possible and contingent, because there was in that place no need
to distinguish them accurately.)

V. By conflicting emotions I mean those which draw a man in
different directions, though they are of the same kind, such as
luxury and avarice, which are both species of love, and are
contraries, not by nature, but by accident.

VI. What I mean by emotion felt towards a thing, future,
present, and past, I explained in III. xviii., notes. i. and ii.,
which see.

(But I should here also remark, that we can only distinctly
conceive distance of space or time up to a certain definite limit;
that is, all objects distant from us more than two hundred
feet, or whose distance from the place where we are exceeds that
which we can distinctly conceive, seem to be an equal distance
from us, and all in the same plane; so also objects, whose time
of existing is conceived as removed from the present by a longer
interval than