The Philosophy of Spinoza by Benedictus de Spinoza (e textbook reader .txt) 📕

idea of that object; that is to say, in so far as He forms the mind of any being. The knowledge, therefore, necessarily exists in God of everything which happens in the object of the idea constituting the human mind; that is to say, it exists in Him in so far as He forms the nature of the human mind; or, whatever happens in the object of the idea constituting the human mind must be perceived by the human mind; in other words, an idea of that thing will necessarily exist in the human mind. That is to say, if the object of the idea constituting the human mind be a body, nothing can happen in that body which is not perceived by the mind.

If the body were not the object of the human mind, the ideas of the modifications of the body would not be in God, in so far as He has formed our mind, but would be in Him in so far as He has formed the mind of another thing; that is to say, the ideas of the modifications of the body would not be in our mind. But we have ideas of the modifications of a body; therefore the object of the idea constituting the human mind is a body, and that, too, actually existing. Again, if there were also any other object of the mind besides a body, since nothing exists from which some effect does not follow, the idea of some effort produced by this object would necessarily exist in our mind. But there is no such idea. Therefore the object of the idea constituting the human mind is a body, or a certain mode of extension actually existing, and nothing else.

Hence it follows that man is composed of mind and body, and that the human body exists as we perceive it.

Hence we see not only that the human mind is united to the body, but also what is to be understood by the union of the mind and body. But no one can understand it adequately or distinctly without knowing adequately beforehand the nature of our body; for those things which we have proved hitherto are altogether general, nor do they refer more to man than to other individuals, all of which are animate, although in different degrees. For of everything there necessarily exists in God an idea of which He is the cause, in the same way as the idea of the human body exists in Him; and therefore everything that we have said of the idea of the human body is necessarily true of the idea of any other thing. We cannot, however, deny that ideas, like objects themselves, differ from one another, and that one is more excellent and contains more reality than another, just as the object of one idea is more excellent and contains more reality than another. Therefore, in order to determine the differences between the human mind and other things and its superiority over them, we must first know, as we have said, the nature of its object, that is to say, the nature of the human body. I am not able to explain it here, nor is such an explanation necessary for what I wish to demonstrate.

This much, nevertheless, I will say generally, that in proportion as one body is better adapted than another to do or suffer many things, in the same proportion will the mind at the same time be better adapted to perceive many things, and the more the actions of a body depend upon itself alone, and the less other bodies coöperate with it in action, the better adapted will the mind be for distinctly understanding. We can thus determine the superiority of one mind to another; we can also see the reason why we have only a very confused knowledge of our body, together with many other things which I shall deduce in what follows.

The Complexity of the Human Mind

The idea which constitutes the formal Being of the human mind is the idea of a body which is composed of a number of individuals composite to a high degree. But an idea of each individual composing the body must necessarily exist in God; therefore the idea of the human body is composed of these several ideas of the component parts. The idea which constitutes the formal Being of the human mind is not simple, but is composed of a number of ideas.

All ways in which any body is affected follow at the same time from the nature of the affected body, and from the nature of the affecting body; therefore the idea of these modifications necessarily involves the nature of each body, and therefore the idea of each way in which the human body is affected by an external body involves the nature of the human body and of the external body.

Hence it follows, in the first place, that the human mind perceives the nature of many bodies together with that of its own body.

It follows, secondly, that the ideas we have of external bodies indicate the constitution of our own body rather than the nature of external bodies.

Imagination

If the human body be affected in a way which involves the nature of any external body, the human mind will contemplate that external body as actually existing or as present, until the human body be affected by a mode which excludes the existence or presence of the external body.

When external bodies so determine the fluid parts of the human body that they often strike upon the softer parts, the fluid parts change the plane of the soft parts, and thence it happens that the fluid parts are reflected from the new planes in a direction different from that in which they used to be reflected, and that also afterwards when they strike against these new planes by their own spontaneous motion, they are reflected in the same way as when they were impelled towards those planes by external bodies. Consequently those fluid bodies produce a modification in the human body while they keep up this reflex motion similar to that produced by the presence of an external body. The mind, therefore, will think as before, that is to say, it will again contemplate the external body as present. This will happen as often as the fluid parts of the human body strike against those planes by their own spontaneous motion. Therefore, although the external bodies by which the human body was once affected do not exist the mind will perceive them as if they were present so often as this action is repeated in the body.

We see, therefore, how it is possible for us to contemplate things which do not exist as if they were actually present. This may indeed be produced by other causes, but I am satisfied with having here shown one cause through which I could explain it, just as if I had explained it through the true cause. I do not think, however, that I am far from the truth, since no postulate which I have assumed contains anything which is not confirmed by an experience that we cannot mistrust, after we have proved the existence of the human body as we perceive it.

We clearly see, moreover, what is the difference between the idea, for example, of Peter, which constitutes the essence of the mind itself of Peter, and the idea of Peter himself which is in another man; for example, in Paul. For the former directly manifests the essence of the body of Peter himself, nor does it involve existence unless so long as Peter exists; the latter, on the other hand, indicates rather the constitution of the body of Paul than the nature of Peter; and therefore so long as Paul's body exists with that constitution, so long will Paul's mind contemplate Peter as present, although he does not exist. But in order that we may retain the customary phraseology, we will give to those modifications of the human body, the ideas of which represent to us external bodies as if they were present, the name of images of things, although they do not actually reproduce the forms of the things. When the mind contemplates bodies in this way, we will say that it imagines. Here I wish it to be observed, in order that I may begin to show what error is, that these imaginations of the mind, regarded by themselves, contain no error, and that the mind is not in error because it imagines, but only in so far as it is considered as wanting in an idea which excludes the existence of those things which it imagines as present. For if the mind, when it imagines non-existent things to be present, could at the same time know that those things did not really exist, it would think its power of imagination to be a virtue of its nature and not a defect, especially if this faculty of imagining depended upon its own nature alone, that is to say, if this faculty of the mind were free.

Association of Ideas and Memory

If the human body has at any time been simultaneously affected by two or more bodies, whenever the mind afterwards imagines one of them, it will also remember the others.

We clearly understand by this what memory is. It is nothing else than a certain concatenation of ideas, involving the nature of things which are outside the human body, a concatenation which corresponds in the mind to the order and concatenation of the modifications of the human body. I say, firstly, that it is a concatenation of those ideas only which involve the nature of things which are outside the human body, and not of those ideas which explain the nature of those things, for there are in truth ideas of the modifications of the human body, which involve its nature as well as the nature of external bodies. I say, in the second place, that this concatenation takes place according to the order and concatenation of the modifications of the human body, that I may distinguish it from the concatenation of ideas which takes place according to the order of the intellect, and enables the mind to perceive things through their first causes, and is the same in all men.

Hence we can clearly understand how it is that the mind from the thought of one thing at once turns to the thought of another thing which is not in any way like the first. For example, from the thought of the word pomum a Roman immediately turned to the thought of the fruit, which has no resemblance to the articulate sound pomum, nor anything in common with it, excepting this, that the body of that man was often affected by the thing and the sound; that is to say, he often heard the word pomum when he saw the fruit. In this manner each person will turn from one thought to another according to the manner in which the habit of each has arranged the images of things in the body. The soldier, for instance, if he sees the footsteps of a horse in the sand, will immediately turn from the thought of a horse to the thought of a horseman, and so to the thought of war. The countryman, on the other hand, from the thought of a horse will turn to the thought of his plow, his field, etc.; and thus each person will turn from one thought to this or that thought, according to the manner in which he has been accustomed to connect and bind together the images of things in his mind.