For, that sorrow consists in the passage to a less perfection, but not in the less perfection itself, no one can deny, since in so far as a man partakes of any perfection, he cannot be sad. Nor can we say that sorrow consists in the passage to a less perfection, for privation is nothing. But the affection of sorrow is actual, and so can be nothing else than the passage to a lesser perfection, that is, the reality by which the power of acting is limited or diminished. As for the definitions of cheerfulness, pleasurable excitement, melancholy, or grief, I omit these, because they are related rather to the body than to the mind, and are merely different species of joy and sorrow. Love is joy with the accompanying idea of an external cause. Hatred is sorrow with the accompanying idea of an external cause. Devotion is love towards an object which we admire and wonder at. Derision is joy arising from the imagination that something we despise is present in the object we hate. Hope is a joy not constant, arising from the idea of something future or past, about the issue of which we are doubtful. Fear is sorrow not constant, arising in like manner. Confidence is joy arising from the idea of a past or future object from which the cause for doubting has been removed. Despair is sorrow arising from a like cause. Confidence springs from hope, despair from fear. Pride is thinking too highly of ourselves from self-love. Despondency is thinking too little of ourselves through sorrow. _IV.--Concerning Human Bondage and Human Liberty_ Good is that which is useful to us; evil, that which impedes the possession of good. But the terms good and evil are not positive, but are only modes of thought, by which we compare one thing with another. Thus, music is good to a melancholy mind, bad to a mourning mind, but neither bad nor good to a deaf man. We suffer because we form a part of nature. The power by which we preserve our being is the power of God, that is part of His essence. But man is subject to passions because he follows the order of nature. An affection can only be overcome by a stronger affection. That which tends to conserve our existence we denominate good. That which hinders this conservation we style evil. Desire springing from the knowledge of good and evil can be restrained by desires originating in the affections by which we are agitated. Thus the effect of external causes on the mind may be far greater than that of the knowledge of good and evil. The desire springing from a knowledge of good and evil may be easily restrained by the desire of present objects. Opinion exercises a more potent influence than reason. Hence the saying of the poet, "I approve the better, but follow the worse." And hence also the preacher says "He that increaseth knowledge increaseth sorrow." We ought to know both the strength and the weakness of our nature, that we may judge what reason can and cannot do in controlling our affections.