SECT.  LXII.  The Idea of the Unity proves that there are Immaterial Substances; and that there is a Being Perfectly One, who is God.

As for units, some perhaps will say that I do not know them by the bodies, but only by the spirits; and, therefore, that my mind being one, and truly known to me, it is by it, and not by the bodies, I have the idea of unity.  But to this I answer.

It will, at least, follow from thence that I know substances that have no manner of extension or divisibility, and which are present.  Here are already beings purely incorporeal, in the number of which I ought to place my soul.  Now, who is it that has united it to my body?  This soul of mine is not an infinite being; it has not been always, and it thinks within certain bounds.  Now, again, who makes it know bodies so different from it?  Who gives it so great a command over a certain body; and who gives reciprocally to that body so great a command over the soul?  Moreover, which way do I know whether this thinking soul is really one, or whether it has parts?  I do not see this soul.  Now, will anybody say that it is in so invisible, and so impenetrable, a thing that I clearly see what unity is?  I am so far from learning by my soul what the being One is, that, on the contrary, it is by the clear idea I have already of unity that I examine whether my soul be one or divisible.

Add to this, that I have within me a clear idea of a perfect unity, which is far above that I may find in my soul.  The latter is often conscious that she is divided between two contrary opinions, inclinations, and habits.  Now, does not this division, which I find within myself, show and denote a kind of multiplicity and composition of parts?  Besides, the soul has, at least, a successive composition of thoughts, one of which is most different and distinct from another.  I conceive an unity infinitely more One, if I may so speak.  I conceive a Being who never changes His thoughts, who always thinks all things at once, and in which no composition, even successive, can be found.  Undoubtedly it is the idea of the perfect and supreme unity that makes me so inquisitive after some unity in spirits, and even in bodies.  This idea, ever present within me, is innate or inborn with me; it is the perfect model by which I seek everywhere some imperfect copy of the unity.  This idea of what is one, simple, and indivisible by excellence can be no other than the idea of God.  I, therefore, know God with such clearness and evidence, that it is by knowing Him I seek in all creatures, and in myself, some image and likeness of His unity.  The bodies have, as it were, some mark or print of that unity, which still flies away in the division of its parts; and the spirits have a greater likeness of it, although they have a successive composition of thoughts.