Some days later he wrote to Cattaneo: “I have here much more need of the exorcist than of the physician, for my trouble is caused by magic art. I will tell you about my goblin. The little thief has robbed me of many crowns; he puts all my books upside down, opens my chests, hides my keys, so that I do not know how to protect myself against him. I am always unhappy, but especially at night, and I do not know if my trouble should be attributed to frenzy.” In another letter: “When I am awake I seem to see lights sparkling in the air; sometimes my eyes are inflamed so that I fear I may lose my sight. At other times I hear horrible noises, hissings, and tinklings, the sound of bells, and, as it were, clocks all striking the hour at the same time. When I am asleep I seem to see a horseman throwing himself on me and casting me to the earth, or else I imagine that I am covered by filthy beasts. All my joints feel it; my head becomes heavy, and in the midst of so many pains and terrors sometimes there appears to me the image of the Virgin, beautiful and young, with her Son, and crowned with a rainbow.” Later he told Cattaneo how a goblin carried away letters in which he was mentioned, “and that is one of the miracles which I saw myself at the hospital. Thus I possess the certainty that these wonders must be attributed to a magician. I have numerous proofs of it. One day a loaf was taken from me, beneath my eyes, towards three o’clock.”

When ill with acute fever he was cured, thanks to an apparition of the Virgin, to whom he testified his gratitude in a sonnet. He wrote and spoke to, almost touched, his genius, who often resembled his former Messaggiero, and suggested to him ideas which he had not conceived before.

Swift, the inventor of irony and humour, predicted even in youth that he would die insane, as had been the case with a paternal uncle. He was walking one day in a garden when he saw an elm almost completely deprived of foliage at the top. “Like that tree,” he said, “I shall die at the top.” Proud almost to monomania with the great, he yet led a wild and vicious life, and was known as the “Mad Parson.” Though a clergyman, he wrote irreligious books, and it was said that before making him a bishop it would be desirable to baptise him. His giddiness began, as he himself tells us, at the age of twenty-three, so that his brain disease lasted for over fifty years. Vertiginosus, inops, surdus, male gratus amicis, as he defined himself, he almost succumbed to the grief caused by the death of his beloved Stella, and at the same time he wrote his burlesque Directions to Servants. Some months later he lost his memory and only preserved his mordant loquacity; he remained for a whole year without speaking or reading or recognising any one; he would walk for ten hours a day, eating his meals standing, or refusing food, and giving way to attacks of rage when any one entered his room. With the development of some boils his condition seemed to improve; he was heard to say several times: “I am a fool;” but the interval of lucidity was short. He fell back into the stupor of dementia, although his irony seemed to survive reason, and even, as it were, life itself. He died in 1745 in a state of complete dementia, leaving by a will made some years previously a sum of nearly £11,000 to a lunatic asylum. A post-mortem examination showed softening of the brain and extreme effusion; his skull (examined in 1855) showed great irregularities from thickening and roughening, signs of enlarged and diseased arteries, and an extremely small cerebellar region. In an epitaph which he had written for himself he summed up the cruel tortures of his soul now at rest, “ubi sæva indignatio ulterius cor lacerare nequit.”

Newton, of whom it was truly said that his mind conquered the human race, was in old age afflicted by mental disorder, though of a less serious character than that of which we have just read. It was probably during this illness that he wrote his Chronology, his Apocalypse, and the Letters to Bentley, so inferior in value to the work of his earlier years. In 1693, after his house had been burnt a second time, and after excess in study, he is reported to have talked so strangely and incoherently to the archbishop that his friends were seriously alarmed. At this time he wrote two letters which, in their confused and obscure form, seem to show that he had been suffering from delusions of persecution. He wrote to Locke (1693): “Being of opinion that you endeavoured to embroil me with women, and by other means, I was so much affected with it, as that when one told me you were sickly and would not live, I answered, ’twere better if you were dead. I desire you to forgive me this uncharitableness; for I am now satisfied that what you have done is just, and I beg your pardon for my having hard thoughts of you for it, and for representing that you struck at the root of morality, in a principle you laid in your book of ideas, and designed to pursue in another book, and that I took you for a Hobbist. I beg your pardon also for saying or thinking that there was a design to sell me an office or to embroil me. I am your most humble and unfortunate servant, Is. Newton.”[172] Locke replied kindly, and a month later Newton again wrote to him: “The last winter, by sleeping too often by my fire, I got an ill habit of sleeping; and a distemper, which this summer has been epidemical, put me further out of order, so that when I wrote to you I had not slept an hour a night for a fortnight together, and for five days together not a wink. I remember I wrote to you, but what I said of your book I remember not.” And in a letter to Pepys he says that he has “neither ate nor slept this twelvemonth, nor have my former consistency of mind.”[173]

Those who, without frequenting a lunatic asylum, wish to form a fairly complete idea of the mental tortures of a monomaniac, have only to look through Rousseau’s works, especially his later writings, such as the Confessions, the Dialogues, and the Rêveries. “I have very ardent passions,” he writes in his Confessions, “and while under their influence, my impetuosity knows no bounds; I think only of the object which occupies me; the entire universe besides is nothing to me; but this only lasts a moment, and the moment which follows throws me into a state of prostration. A single sheet of fine paper tempts me more than the money to buy a ream of it. I see the thing and am tempted; if I only see the means of acquiring it I am not tempted. Even now, if I see anything that tempts me, I prefer taking it to asking for it.”

This is the distinction between the kleptomaniac and the thief: the former steals by instinct, to steal; the latter steals by interest, to acquire: the first is led away by anything that strikes him; the second is attracted by the value of the object.

Dominated by his senses, Rousseau never knew how to resist them. The most insignificant pleasure, he says, so long as it was present, fascinated him more than all the joys of Paradise. In fact, a monk’s dinner (Father Pontierre) led him to apostasy, and a feeling of repulsion caused him to abandon cruelly an epileptic friend on the road.

It was not only his passions that were morbid and violent; his intelligence also was affected from his earliest days, as he shows in his Confessions: “My imagination has never been so cheerful as when I have been suffering. My mind cannot beautify the really pleasant things that happen to me, only the imaginary ones. If I wish to describe spring well, it must be in winter.” Real evils had little hold on Rousseau, he tells us; imaginary evils touched him more nearly. “I can adapt myself to what I experience, but not to what I fear.” It is thus that people kill themselves through fear of death.

On first reading medical books Rousseau imagined that he had the diseases which he found described, and was astonished, not to find himself healthy, but to find himself alive. He came to the conclusion that he had a polypus at the heart. It was, as he himself confesses, a strange notion, the overflow of an idle and exaggerated sensibility which had no better channel. “There are times,” he says, “in which I am so little like myself that I might be taken for a man of quite different character. In repose I am indolence and timidity itself, and do not know how to express myself; but if I become excited I immediately know what to say.”

This unfortunate man went through a long series of occupations from the noblest to the most degrading; he was an apostate for money, a watchmaker, a charlatan, a music-master, an engraver, a painter, a servant, an embryo diplomatic secretary; in literature and science he took up medicine, music, botany, theology, teaching.