Subsection 6 Excessive exercise as a cause, and how it acts. Solitude and idleness.

Nothing is so good that it cannot be misused. Nothing is better than exercise, taken at the right time, for preserving the body; nothing worse when it is ill-timed, violent or excessive. Fernel, citing Galen in his Pathology, book 1, chapter 16, says that excessive exercise and exhaustion consume the spirits and bodily substance and chill the body. They stir up and inflame humours that nature would otherwise have processed and expelled; once inflamed, these affect and disturb body and mind in various ways.

The same happens when exercise is taken at the wrong time, on a full stomach or when the body is full of undigested matter. Fuchs strongly attacks this in Institutes, book 2, section 2, chapter 4, explaining that German schoolboys so often have scabby skin because they exercise immediately after meals. Bayerus warns against such exercise because it spoils the food in the stomach and carries its juice, still raw and undigested, into the veins, says Lemnius, where it putrefies and disrupts the animal spirits.

Crato, consultation 21, book 2, protests against all such exercise after meals as the greatest possible enemy of digestion and a cause of corrupted humours, which produce this and many other diseases. Not without good reason, then, do Sallustius Salvianus, book 2, chapter 1; Leonartus Jacchinus, on book 9 of Rhazes; Mercurialis; Arculanus; and many others list excessive exercise as a most powerful cause of melancholy.

The opposite of exercise is idleness—the badge of gentility—or lack of exercise: the ruin of body and mind, the nurse of wickedness, the stepmother of discipline, the chief author of all mischief, one of the seven deadly sins, and a cause sufficient by itself to produce this and many other illnesses. It is the devil’s cushion, as Gualter calls it, his pillow and favourite resting place. For the mind can never rest: it is always thinking about something, and unless occupied with some worthwhile business, it rushes of its own accord into melancholy.

Just as excessive and violent exercise does harm at one extreme, says Crato, an idle life does so at the other: it fills the body with phlegm, thick humours, all kinds of blockages, rheums, catarrhs and so on. Rhazes, Continens, book 1, treatise 9, counts it the greatest cause of melancholy. “I have often seen,” he says, “that idleness breeds this humour more than anything else.” Montaltus, chapter 1, supports him from his own experience: idle people are far more prone to melancholy than those engaged in some duty or business.

Plutarch counts idleness a cause sufficient by itself to produce sickness of the soul: some people, he says, are troubled in mind for no other reason. Homer, Iliad, book 1, presents Achilles eating his heart out in idleness because he could not fight. Mercurialis, consultation 86, on a melancholy young man, insists that it is a chief cause. Why was he melancholy? Because he was idle. Nothing breeds it sooner or more often increases and prolongs it than idleness.

It is a disease familiar to all idle people, an inseparable companion to those who live at ease, “passing their days lazily in comfortable leisure,” inactive, with no calling or regular occupation to keep them busy, and little demanding their attention. Even when something does, their laziness and sluggishness are such that they will not settle down to do anything. They cannot bear work, however necessary or easy—dressing themselves, writing a letter or the like.

Yet, like someone numb with cold who sits shivering although a little movement or exercise would bring relief, they complain but will not use the easy and available means of helping themselves; and so melancholy continues to torment them. Especially when they have been accustomed to business or to much company and suddenly begin a sedentary life, it tortures their souls and seizes them in an instant.

For while they are occupied in any way—with activity, conversation, business, sport or recreation, or with company they enjoy—they are very well; but once alone or idle, they are immediately tormented again. A day’s solitude, sometimes a single hour’s, harms them more than a week of medicine, work and company can help them. Melancholy seizes them as soon as they are alone and tortures them so much that, as wise Seneca well says, “I would rather live in hardship than in softness”—I would rather be sick than idle.

This idleness belongs either to the body or to the mind. Bodily idleness is simply a kind of numbing laziness, a cessation of exercise which, if we may believe Fernel, causes undigested matter, blockages and waste humours; extinguishes the natural heat; dulls the spirits; and makes them unfit to do anything whatsoever. “In neglected fields grows fern that must be burned.”

As fern and every kind of weed grow on untilled ground, so thick humours grow in an idle body: “Idleness corrupts the inactive body.” A horse kept in a stable that never travels, a hawk kept in a mew that seldom flies, are both subject to diseases from which they are largely free when left to themselves. An idle dog will become mangy; how can an idle person expect to escape?

Idleness of mind is much worse than bodily idleness. Intelligence without employment is a disease, “corrosion of the mind, rust of the intellect”—the rust of the soul, a plague, a hell in itself. Galen calls it “the greatest injury to the mind.” Just as worms and filthy crawling things multiply in a stagnant pool—and “waters become foul unless they are stirred”; the water itself putrefies, and air likewise unless the wind continually stirs it—so evil and corrupt thoughts multiply in an idle person, and the soul is contaminated.

In a commonwealth with no external enemy, civil wars are likely, and people turn their fury on themselves. So this body of ours, when idle and at a loss how to occupy itself, wastes and torments itself with cares, sorrows, groundless fears, discontents and suspicions. It tortures and preys upon its own entrails and is never at rest.