there should be any such idea. And this if I mistake not has been
demonstrated in section 27; to which I shall here add that a spirit
has been shewn to be the only substance or support wherein
unthinking beings or ideas can exist; but that this substance which
supports or perceives ideas should itself be an idea or like an idea
is evidently absurd.

  136. It will perhaps be said that we want a sense (as some have
imagined) proper to know substances withal, which, if we had, we might
know our own soul as we do a triangle. To this I answer, that, in case
we had a new sense bestowed upon us, we could only receive thereby
some new sensations or ideas of sense. But I believe nobody will say
that what he means by the terms soul and substance is only some
particular sort of idea or sensation. We may therefore infer that, all
things duly considered, it is not more reasonable to think our
faculties defective, in that they do not furnish us with an idea of
spirit or active thinking substance, than it would be if we should
blame them for not being able to comprehend a round square.

  137. From the opinion that spirits are to be known after the
manner of an idea or sensation have risen many absurd and heterodox
tenets, and much scepticism about the nature of the soul. It is even
probable that this opinion may have produced a doubt in some whether
they had any soul at all distinct from their body since upon inquiry
they could not find they had an idea of it. That an idea which is
inactive, and the existence whereof consists in being perceived,
should be the image or likeness of an agent subsisting by itself,
seems to need no other refutation than barely attending to what is
meant by those words. But, perhaps you will say that though an idea
cannot resemble a spirit in its thinking, acting, or subsisting by
itself, yet it may in some other respects; and it is not necessary
that an idea or image be in all respects like the original.

  138. I answer, if it does not in those mentioned, it is impossible
it should represent it in any other thing. Do but leave out the
power of willing, thinking, and perceiving ideas, and there remains
nothing else wherein the idea can be like a spirit. For, by the word
spirit we mean only that which thinks, wills, and perceives; this, and
this alone, constitutes the signification of the term. If therefore it
is impossible that any degree of those powers should be represented in
an idea, it is evident there can be no idea of a spirit.

  139. But it will be objected that, if there is no idea signified
by the terms soul, spirit, and substance, they are wholly
insignificant, or have no meaning in them. I answer, those words do
mean or signify a real thing, which is neither an idea nor like an
idea, but that which perceives ideas, and wills, and reasons about
them. What I am myself, that which I denote by the term I, is the same
with what is meant by soul or spiritual substance. If it be said
that this is only quarreling at a word, and that, since the
immediately significations of other names are by common consent called
ideas, no reason can be assigned why that which is signified by the
name spirit or soul may not partake in the same appellation. I answer,
all the unthinking objects of the mind agree in that they are entirely
passive, and their existence consists only in being perceived; whereas
a soul or spirit is an active being, whose existence consists, not
in being perceived, but in perceiving ideas and thinking. It is
therefore necessary, in order to prevent equivocation and
confounding natures perfectly disagreeing and unlike, that we
distinguish between spirit and idea. See sect. 27.

  140. In a large sense, indeed, we may be said to have an idea or
rather a notion of spirit; that is, we understand the meaning of the
word, otherwise we could not affirm or deny anything of it.
Moreover, as we conceive the ideas that are in the minds of other
spirits by means of our own, which we suppose to be resemblances of
them; so we know other spirits by means of our own soul- which in that
sense is the image or idea of them; it having a like respect to
other spirits that blueness or heat by me perceived has to those ideas
perceived by another.

  141. It must not be supposed that they who assert the natural
immortality of the soul are of opinion that it is absolutely incapable
of annihilation even by the infinite power of the Creator who first
gave it being, but only that it is not liable to be broken or
dissolved by the ordinary laws of nature or motion. They indeed who
hold the soul of man to be only a thin vital flame, or system of
animal spirits, make it perishing and corruptible as the body; since
there is nothing more easily dissipated than such a being, which it is
naturally impossible should survive the ruin of the tabernacle wherein
it is enclosed. And this notion has been greedily embraced and
cherished by the worst part of mankind, as the most effectual antidote
against all impressions of virtue and religion. But it has been made
evident that bodies, of what frame or texture soever, are barely
passive ideas in the mind, which is more distant and heterogeneous
from them than light is from darkness. We have shewn that the soul
is indivisible, incorporeal, unextended, and it is consequently
incorruptible. Nothing can be plainer than that the motions,
changes, decays, and dissolutions which we hourly see befall natural
bodies (and which is what we mean by the course of nature) cannot
possibly affect an active, simple, uncompounded substance; such a
being therefore is indissoluble by the force of nature; that is to
say, "the soul of man is naturally immortal."

  142. After what has been said, it is, I suppose, plain that our
souls are not to be known in the same manner as senseless, inactive
objects, or by way of idea. Spirits and ideas are things so wholly
different, that when we say "they exist," "they are known," or the
like, these words must not be thought to signify anything common to
both natures. There is nothing alike or common in them: and to