The City of God/Book XI/Chapter 27
And truly the very fact of existing is by some natural spell so pleasant, that even the wretched are, for no other reason, unwilling to perish; and, when they feel that they are wretched, wish not that they themselves be annihilated, but that their misery be so. Take even those who, both in their own esteem, and in point of fact, are utterly wretched, and who are reckoned so, not only by wise men on account of their folly, but by those who count themselves blessed, and who think them wretched because they are poor and destitute,—if any one should give these men an immortality, in which their misery should be deathless, and should offer the alternative, that if they shrank from existing eternally in the same misery they might be annihilated, and exist nowhere at all, nor in any condition, on the instant they would joyfully, nay exultantly, make election to exist always, even in such a condition, rather than not exist at all. The well-known feeling of such men witnesses to this. For when we see that they fear to die, and will rather live in such misfortune than end it by death, is it not obvious enough how nature shrinks from annihilation? And, accordingly, when they know that they must die, they seek, as a great boon, that this mercy be shown them, that they may a little longer live in the same misery, and delay to end it by death. And so they indubitably prove with what glad alacrity they would accept immortality, even though it secured to them endless destruction. What! do not even all irrational animals, to whom such calculations are unknown, from the huge dragons down to the least worms, all testify that they wish to exist, and therefore shun death by every movement in their power? Nay, the very plants and shrubs, which have no such life as enables them to shun destruction by movements we can see, do not they all seek in their own fashion to conserve their existence, by rooting themselves more and more deeply in the earth, that so they may draw nourishment, and throw out healthy branches towards the sky? In fine, even the lifeless bodies, which want not only sensation but seminal life, yet either seek the upper air or sink deep, or are balanced in an intermediate position, so that they may protect their existence in that situation where they can exist in most accordance with their nature.
And how much human nature loves the knowledge of its existence, and how it shrinks from being deceived, will be sufficiently understood from this fact, that every man prefers to grieve in a sane mind, rather than to be glad in madness. And this grand and wonderful instinct belongs to men alone of all animals; for, though some of them have keener eyesight than ourselves for this world’s light, they cannot attain to that spiritual light with which our mind is somehow irradiated, so that we can form right judgments of all things. For our power to judge is proportioned to our acceptance of this light. Nevertheless, the irrational animals, though they have not knowledge, have certainly something resembling knowledge; whereas the other material things are said to be sensible, not because they have senses, but because they are the objects of our senses. Yet among plants, their nourishment and generation have some resemblance to sensible life. However, both these and all material things have their causes hidden in their nature; but their outward forms, which lend beauty to this visible structure of the world, are perceived by our senses, so that they seem to wish to compensate for their own want of knowledge by providing us with knowledge. But we perceive them by our bodily senses in such a way that we do not judge of them by these senses. For we have another and far superior sense, belonging to the inner man, by which we perceive what things are just, and what unjust,—just by means of an intelligible idea, unjust by the want of it. This sense is aided in its functions neither by the eyesight, nor by the orifice of the ear, nor by the air-holes of the nostrils, nor by the palate’s taste, nor by any bodily touch. By it I am assured both that I am, and that I know this; and these two I love, and in the same manner I am assured that I love them.