Appendix: Reasons Which Establish the Existence of God, and the Distinction Between the Mind and Body of Man, Disposed I

(from the reply to the second objections — latin, 1670. pp. 85-91. french, garnier. tom. II., pp 74-84.)

I. By the term thought (cogitatio, pensée), I comprehend all that is in us, so that we are immediately conscious of it. Thus, all the operations of the will, intellect, imagination, and senses, are thoughts. But I have used the word immediately expressly to exclude whatever follows or depends upon our thoughts: for example, voluntary motion has, in truth, thought for its source (principle), but yet it is not itself thought. [Thus walking is not a thought, but the perception or knowledge we have of our walking is.]

II. By the word idea I understand that form of any thought, by the immediate perception of which I am conscious of that same thought; so that I can express nothing in words, when I understand what I say, without making it certain, by this alone, that I possess the idea of the thing that is signified by these words. And thus I give the appellation idea not to the images alone that are depicted in the phantasy; on the contrary, I do not here apply this name to them, in so far as they are in the corporeal phantasy, that is to say, in so far as they are depicted in certain parts of the brain, but only in so far as they inform the mind itself, when turned toward that part of the brain.

III. By the objective reality or an idea i understand the entity or being of the thing represented by the idea, in so far as this entity is in the idea; and, in the same manner, it may be called either an objective perfection, or objective artifice, etc. (artificium objectivum). For all that we conceive to be in the objects of the ideas is objectively [or by representation] in the ideas themselves.

IV. The same things are said to be formally in the objects of the ideas when they are in them such as we conceive them; and they are said to be in the objects eminently when they are not indeed such as we conceive them, but are so great that they can supply this defect by their excellence.

V. Everything in which there immediately resides, as in a subject, or by which there exists any object we perceive, that is, any property, or quality, or attribute of which we have in us a real idea, is called substance. For we have no other idea of substance, accurately taken, except that it is a thing in which exists formally or eminently this property or quality which we perceive, or which is objectively in some one of our ideas, since we are taught by the natural light that nothing can have no real attribute.

VI. The substance in which thought immediately resides is here called mind (mens, esprit). I here speak, however, of mens rather than of anima, for the latter is equivocal, being frequently applied to denote a corporeal object.

VII. The substance which is the immediate subject of local extension, and of the accidents that presuppose this extension, as figure, situation, local motion, etc., is called body. But whether the substance which is called mind be the same with that which is called body, or whether they are two diverse substances, is a question to be hereafter considered.

VIII. The substance which we understand to be supremely perfect, and in which we conceive nothing that involves any defect, or limitation of perfection, is called God.

IX. When we say that some attribute is contained in the nature or concept of a thing, this is the same as if we said that the attribute is true of the thing, or that it may be affirmed of the thing itself.

X. Two substances are said to be really distinct, when each of them may exist without the other.