The Nature and Properties of the Understanding

Error is:

• the cause of human misery
• the evil principle that has produced evil in the world
• what has given rise to and maintains the ills that afflict us

Holy Scripture teaches us that men:

• are miserable only because they are sinners and criminals
• would be neither sinners nor criminals if they did not consent to error.

If error is the origin of human misery, then men should make an effort to free themselves from it.

Certainly their effort will not be useless and without reward, even if it does not have all the effect they might wish. If men do not become infallible, they will be mistaken much less often, and if they do not entirely free themselves from their ills, they will at least avoid some of them.

In this life one must not hope for complete happiness, because here below one must not aspire to infallibility; but one must work ceaselessly not to be mistaken, since one ceaselessly wishes to be freed from one’s miseries.

Just as one ardently desires a happiness without hoping for it, one must strive with effort toward infallibility without aspiring to it.

One must not imagine that there is much to suffer in the search for truth; one need only pay attention to the clear ideas that each person finds within himself, and follow exactly a few rules that we will give later. Exactness of mind has almost nothing painful about it; it is not a servitude as the imagination represents it; and if we initially find some difficulty in it, we soon receive satisfactions that abundantly reward us for our pains; for in the end, it is only this exactness that produces light and reveals truth to us.

But without lingering further to prepare the minds of readers, whom it is much more fitting to believe are sufficiently inclined of themselves to the search for truth, let us examine the causes and the nature of our errors; and since the method that examines things by considering them in their birth and origin has more order and clarity, and makes them known more thoroughly than others, let us try to employ it here.

The Nature and Properties of the Will, and What Freedom Is

The human mind, being neither material nor extended, is without doubt a simple substance, indivisible, and without any composition of parts; but nevertheless one is accustomed to distinguish in it two faculties, namely: the understanding and the will, which it is necessary to explain first, for it seems that the notions or ideas that one has of these two faculties are not clear or distinct enough.

But because these ideas are very abstract and do not fall under the imagination, it seems appropriate to express them in relation to the properties that belong to matter, which, being easily imaginable, will make the notions that it is good to attach to these two words — understanding and will — more distinct and even more familiar. One need only take care that these comparisons between mind and matter are not entirely exact, and that we compare these two things together only to render the mind more attentive and to make others, as it were, feel what we mean to say.

Matter, or extension, contains within itself two properties or two faculties. The first faculty is that of receiving different shapes, and the second is the capacity to be moved. Likewise, the human mind contains two faculties: the first, which is the understanding, is that of receiving several ideas, that is to say, of perceiving several things; the second, which is the will, is that of receiving several inclinations, or of willing different things. We will first explain the comparisons that are found between the first of the two faculties that belong to matter and the first of those that belong to the mind.

Extension is capable of receiving two kinds of shapes. Some are only external, like roundness in a piece of wax; others are internal, and these are those that are proper to all the small parts of which the wax is composed; for it is indisputable that all the small parts that compose a piece of wax have shapes very different from those that compose a piece of iron. I therefore call simply shape that which is external, and I call configuration the shape that is internal and necessary to all the parts of which the wax is composed, in order for it to be what it is.

One can say similarly that the perceptions that the soul has of ideas are of two kinds. The first, which are called pure perceptions, are, so to speak, superficial to the soul; they do not penetrate or modify it noticeably. The second, which are called sensible perceptions, penetrate it more or less vividly. Such are pleasure and pain, light and colors, tastes, odors, etc. For it will be shown later that sensations are nothing other than ways of being of the mind; and this is why I will call them modifications of the mind.

One could also call the inclinations of the soul modifications of the same soul. For since it is certain that the inclination of the will is a way of being of the soul, one could call it a modification of the soul; just as movement in bodies, being a way of being of those same bodies, one could say that movement is a modification of matter. However, I do not call the inclinations of the will or the movements of matter modifications, because these inclinations and these movements ordinarily relate to something external, for inclinations relate to good, and movements relate to some external body. But the shapes and configurations of bodies and the sensations of the soul have no necessary relation to the outside. For just as a shape is round when all the external parts of a body are equally distant from one of its parts called the center, without any relation to external things, so all the sensations of which we are capable could subsist even if there were no object outside us. Their being does not involve any necessary relation with the bodies that seem to cause them, as will be proved elsewhere; and they are nothing other than the soul modified in such and such a way; so that they are properly the modifications of the soul. Let me therefore be permitted to call them thus in order to make myself clear.

The first and principal of the similarities found between the faculty that matter has of receiving different shapes and different configurations, and that which the soul has of receiving different ideas and different modifications, is that just as the faculty of receiving different shapes and different configurations in bodies is entirely passive and involves no action, so the faculty of receiving different ideas and different modifications in the mind is entirely passive and involves no action; and I call this faculty or this capacity that the soul has to receive all these things, the UNDERSTANDING.

From this it must be concluded that it is the understanding that perceives or knows, since it is only the understanding that receives the ideas of objects; for it is the same thing for the soul to perceive an object as to receive the idea that represents it. It is also the understanding that perceives the modifications of the soul or that feels them, since by this word understanding I mean this passive faculty of the soul by which it receives all the different modifications of which it is capable. For it is the same thing for the soul to receive the way of being called pain as to perceive or feel pain; since it can receive pain in no other way than by perceiving it. From this one can conclude that it is the understanding that imagines absent objects and feels those that are present; and that the senses and the imagination are only the understanding perceiving objects through the organs of the body, as we will explain later.

Now, because when one feels pain or something else one ordinarily perceives it through the intermediary of the sense organs, men ordinarily say that it is the senses that perceive it, without distinctly knowing what they mean by the term senses. They think that there is some faculty distinct from the soul that makes it, or the body, capable of feeling; for they believe that the sense organs truly have a part in our perceptions. They imagine that the body helps the mind to feel so much that if the mind were separated from the body it could never feel anything. But they think all these things only through prejudice and because in our present state we never feel anything without the use of the sense organs, as we will explain elsewhere at greater length.

It is in order to accommodate ourselves to the ordinary way of speaking that we will say later that the senses feel; but by the word senses we understand nothing other than this passive faculty of the soul of which we have just spoken, that is to say, the understanding perceiving something on the occasion of what occurs in the organs of its body, according to the institution of nature, as will be explained elsewhere.

The other similarity between the passive faculty of the soul and that of matter is that, just as matter is not truly changed by the change that occurs in its shape — I mean, for example, that wax does not undergo any considerable change for being round or square — so the mind does not undergo any considerable change through the diversity of the ideas it has; I mean that the mind does not undergo any considerable change, even though it receives the idea of a square or a round, in perceiving a square or a round.

Moreover, just as one can say that matter undergoes considerable changes when it loses the configuration proper to the parts of wax to receive that which is proper to fire and smoke, when wax changes into fire and smoke, so one can say that the soul undergoes very considerable changes when it changes its modifications and suffers pain after having felt pleasure. From this it must be concluded that pure perceptions are to the soul roughly what shapes are to matter, and that configurations are to matter roughly what sensations are to the soul. But one must not imagine that the comparison is exact; I make it only to make the notion of this word understanding intelligible; I will explain the nature of ideas in the third book.

II. The other faculty of matter is that it is capable of receiving several movements, and the other faculty of the soul is that it is capable of receiving several inclinations. Let us compare these faculties together.

Just as the author of nature is the universal cause of all the movements found in matter, so He is also the general cause of all the natural inclinations found in minds; and just as all movements proceed in a straight line if they do not encounter some external and particular causes that determine and change them into curved lines through their opposition, so all the inclinations we have from God are straight, and they could have no other end than the possession of good and truth if there were no external cause that determined the impression of nature toward evil ends. Now, it is this external cause that is the cause of all our ills and that corrupts all our inclinations.

To understand this well, one must know that there is a very considerable difference between the impression or movement that the author of nature produces in matter, and the impression or movement toward the good in general that the same author of nature continuously impresses on the mind. For matter is entirely without action; it has no force to stop its movement, nor to determine and turn it one way rather than another. Its movement, as just said, always proceeds in a straight line, and when it is prevented from continuing in this way, it describes the largest possible circular line, and consequently the one closest to the straight line, because it is God who imparts its movement to it and who regulates its determination. But it is not the same with the will: one can say in a sense that it is active and that it has within itself the force to determine variously the inclination or impression that God gives it; for although it cannot stop this impression, it can in a sense turn it wherever it pleases, and thus cause all the disorder that is found in its inclinations, and all the miseries that are the necessary and certain consequences of sin.

So that by this word WILL, I intend here to designate the impression or natural movement that carries us toward the indeterminate and general good; and by the word FREEDOM, I mean nothing other than the force that the mind has to turn this impression toward the objects that please us, and thus to cause our natural inclinations to be directed toward some particular object, whereas previously they were vague and indeterminate toward the good in general or universal, that is to say, toward God, who alone is the general good, because He alone contains all goods within Himself.

From this it is easy to recognize that, although natural inclinations are voluntary, they are nevertheless not free with the freedom of indifference of which I speak, which involves the power to will or not to will, or to will the opposite of what our natural inclinations carry us toward. For although one loves the good in general voluntarily and freely, since one can love only by one’s will and it is a contradiction that the will could ever be constrained, yet one does not love it freely in the sense I have just explained, since it is not within the power of our will not to wish to be happy.

But one must note well that the mind, considered as impelled toward the good in general, cannot determine its movement toward some particular good unless the same mind, considered as capable of ideas, has knowledge of that particular good. I mean, to use ordinary terms, that the will is a blind power, which can move only toward the things that the understanding represents to it. So that the will cannot variously determine the impression it has for the good, and all its natural inclinations, except by commanding the understanding to represent to it some particular object. The force that the will has to determine its inclinations therefore necessarily includes the power to direct the understanding toward the objects that please it.

I make sensible by an example what I have just said about the will and freedom. A person represents to himself some dignity as a good that he can hope for; immediately his will desires this good, that is to say, the impression that the mind continuously receives toward the indeterminate and universal good carries it toward this dignity. But since this dignity is not the universal good, and is not considered by a clear and distinct view of the mind as the universal good (for the mind never sees clearly what is not), the impression we have toward the universal good is not entirely stopped by this particular good. The mind has movement to go further; it does not love this dignity necessarily or invincibly, and it is free with respect to it. Now its freedom consists in this: that, not being fully convinced that this dignity contains all the good that it is capable of loving, it can suspend its judgment and its love; and then, as we will explain in the third book, it can, through its union with the universal being or with Him who contains all good, think of other things and consequently love other goods. Finally, it can compare all goods, love them according to order, in proportion as they are lovable, and relate them all to that One who contains them all and who alone is worthy of setting a limit to our love, as being alone capable of filling all the capacity we have for loving.

It is roughly the same with the knowledge of truth as with the love of good. We love the knowledge of truth, just as we love the enjoyment of good, by a natural impression; and this impression, as well as that which carries us toward good, is not invincible; it becomes such only through evidence, or through a perfect and complete knowledge of the object; and we are as free in our false judgments as in our disordered loves, as we will show in the following chapter.