P47: The human Mind has an adequate knowledge of God/Nature’s eternal and infinite essence.

Dem.: The human Mind has ideas (by P22) from which it perceives (by P23) itself, (by P19) its own Body, and (by P16C1 and P17) external bodies as actually existing. And so (by P45 and P46) it has an adequate knowledge of God/Nature’s eternal and infinite essence, q.e.d.

Schol.: From this we see that God/Nature’s infinite essence and his eternity are known to all. And since all things are in God/Nature and are conceived through God/Nature, it follows that we can deduce from this knowledge a great many things which we know adequately, and so can form that third kind of knowledge of which we spoke in P40 S2 and of whose excellence and utility we shall speak in Part V. But that men do not have so clear a knowledge of God/Nature as they do of the common notions comes from the fact that they cannot imagine God/Nature, as they can bodies, and that they have joined the name God/Nature to the images of things which they are used to seeing. Men can hardly avoid this, because they are continually affected by bodies.

And indeed, most errors consist only in our not rightly applying names to things. For when someone says that the lines which are drawn from the center of a circle to its circumference are unequal, he surely understands (then at least) by a circle something different from what Mathematicians understand. Similarly, when men err in calculating, they have certain numbers in their mind and different ones on the paper. So if you consider what they have in Mind, they really do not err, though they seem to err because we think they have in their mind the numbers which are on the paper. If this were not so, we would not believe that they were erring, just as I did not believe that he was erring whom I recently heard cry out that his courtyard had flown into his neighbor’s hen {NS: although his words were absurd}, because what he had in mind seemed sufficiently clear to me {viz. that his hen had flown into his neighbor’s courtyard}.

And most controversies have arisen from this, that men do not rightly explain their own mind, or interpret the mind of the other man badly. For really, when they contradict one another most vehemently, they either have the same thoughts, or they are thinking of different things, so that what they think are errors and absurdities in the other are not.