The Philosophy of Spinoza

by Benedictus de Spinoza

Besides these two kinds of knowledge, there is a third, as I shall hereafter show, which we shall call intuitive science. This kind of knowing advances from an adequate idea of the formal essence of certain attributes of God to the adequate knowledge of the essence of things. All this I will explain by one example. Let there be three numbers given through which it is required to discover a fourth which shall be to the third as the second is to the first. A merchant does not hesitate to multiply the second and third together and divide the product by the first, either because he has not yet forgotten the things which he heard without any demonstration from his school-master, or because he has seen the truth of the rule with the more simple numbers, or because from the 19th Prop. in the 7th book of Euclid he understands the common property of all proportionals.

But with the simplest numbers there is no need of all this. If the numbers 1, 2, 3, for instance, be given, every one can see that the fourth proportional is 6 much more clearly than by any demonstration, because from the ratio in which we see by one intuition that the first stands to the second we conclude the fourth.

To knowledge of the first kind we have said that all those ideas belong which are inadequate and confused, and, therefore, this knowledge alone is the cause of falsity. Moreover, to knowledge of the second and third kind we have said that those ideas belong which are adequate, and therefore this knowledge is necessarily true.

It is the knowledge of the second and third, and not that of the first kind, which teaches us to distinguish the true from the false. For he who knows how to distinguish between the true and the false must have an adequate idea of the true and the false, that is to say, he must know the true and the false by the second or third kind of knowledge.

Reason and Imagination

It is in the nature of reason to perceive things truly, that is to say, as they are in themselves, that is to say, not as contingent but as necessary.

Hence it follows that it is through the imagination alone that we look upon things as contingent both with reference to the past and the future.

How this happens I will explain in a few words. We have shown above that unless causes occur preventing the present existence of things, the mind always imagines them present before it, even if they do not exist. Again, we have shown that if the human body has once been simultaneously affected by two external bodies, whenever the mind afterwards imagines one it will immediately remember the other; that is to say, it will look upon both as present before it, unless causes occur which prevent the present existence of the things. No one doubts, too, that we imagine time because we imagine some bodies to move with a velocity less, or greater than, or equal to that of others.

Let us therefore suppose a boy who yesterday, for the first time, in the morning saw Peter, at midday Paul, in the evening Simeon, and to-day in the morning again sees Peter. It is plain that as soon as he sees the morning light he will imagine the sun passing through the same part of the sky as on the day preceding; that is to say, he will imagine the whole day, and at the same time Peter will be connected in his imagination with the morning, Paul with midday, and Simeon with the evening. In the morning, therefore, the existence of Paul and Simeon will be imagined in relation to future time, while in the evening, if the boy should see Simeon, he will refer Peter and Paul to the past, since they will be connected with the past in his imagination. This process will be constant in proportion to the regularity with which he sees Peter, Paul, and Simeon in this order. If it should by some means happen that on some other evening, in the place of Simeon, he should see James, on the following morning he will connect in his imagination with the evening at one time Simeon and at another James, but not both together. For he is supposed to have seen one and then the other in the evening, but not both together. His imagination will therefore fluctuate, and he will connect with a future evening first one and then the other; that is to say, he will consider neither as certain, but both as a contingency in the future.

This fluctuation of the imagination will take place in the same way if the imagination is dealing with things which we contemplate in the same way with reference to past or present time, and consequently we imagine things related to time past, present, or future as contingent.