The Philosophy of Spinoza · Benedictus de Spinoza
II
_Explanation._--I say, in the first place, that an emotion or passion of the mind _is a confused idea_. For we have shown that the mind suffers only in so far as it has inadequate or confused ideas. I say again, _by which the mind affirms of its body, or any part of it, a greater or less power of existence than before_. For all ideas which we possess of bodies indicate the actual constitution of our body rather than the nature of the external body; but this idea, which constitutes the form of an emotion, must indicate or express the constitution of the body, or of some part of it; which constitution the body or any part of it possesses from the fact that its power of action or force of existence is increased or diminished, helped or limited. But it is to be observed, that when I say _a greater or less power of existence than before_, I do not mean that the mind compares the present with the past constitution of the body, but that the idea which constitutes the form of emotion affirms something of the body which actually involves more or less reality than before.
Moreover, since the essence of the mind consists in its affirmation of the actual existence of its body, and since we understand by perfection the essence itself of the thing, it follows that the mind passes to a greater or less perfection when it is able to affirm of its body, or some part of it, something which involves a greater or less reality than before. When, therefore, I have said that the mind's power of thought is increased or diminished, I have wished to be understood as meaning nothing else than that the mind has formed an idea of its body, or some part of its body, which expresses more or less reality than it had hitherto affirmed of the body. For the value of ideas and the actual power of thought are measured by the value of the object. Finally, I added, _which being given, the mind itself is determined to one particular thought rather than to another_, that I might also express the nature of desire in addition to that of joy and sorrow, which is explained by the first part of the definition.
I have now, I think, explained the principal emotions and vacillations of the mind which are compounded of the three primary emotions, desire, joy, and sorrow, and have set them forth through their first causes. From what has been said it is plain that we are disturbed by external causes in a number of ways, and that, like the waves of the sea agitated by contrary winds, we fluctuate in our ignorance of our future and destiny. I have said, however, that I have only explained the principal mental complications, and not all which may exist. For by the same method which we have pursued above it would be easy to show that love unites itself to repentance, scorn, shame, etc.; but I think it has already been made clear to all that the emotions can be combined in so many ways, and that so many variations can arise, that no limits can be assigned to their number. It is sufficient for my purpose to have enumerated only those which are of consequence; the rest, of which I have taken no notice, being more curious than important.
There is one constantly recurring characteristic of love which I have yet to notice, and that is, that while we are enjoying the thing which we desired, the body acquires from that fruition a new disposition by which it is otherwise determined, and the images of other things are excited in it, and the mind begins to imagine and to desire other things. For example, when we imagine anything which usually delights our taste, we desire to enjoy it by eating it. But whilst we enjoy it the stomach becomes full, and the constitution of the body becomes altered. If, therefore, the body being now otherwise disposed, the image of the food, in consequence of its being present, and therefore also the effort or desire to eat it, become more intense, then this new disposition of the body will oppose this effort or desire, and consequently the presence of the food which we desired will become hateful to us, and this hatefulness is what we call loathing or disgust. As for the external modifications of the body which are observed in the emotions, such as trembling, paleness, sobbing, laughter, and the like, I have neglected to notice them, because they belong to the body alone without any relationship to the mind. [26] Hence it follows that the mind is subject to passions in proportion to the number of inadequate ideas which it has, and that it acts in proportion to the number of adequate ideas which it has. [27] This proposition is self-evident, for the definition of any given thing affirms and does not deny the existence of the thing; that is to say, it posits the essence of the thing and does not negate it. So long, therefore, as we attend only to the thing itself, and not to external causes, we shall discover nothing in it which can destroy it.
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