Page:The Great Didactic of John Amos Comenius (1896).pdf/273

 on the body, an impression will be made on the soul also. We may therefore unhesitatingly say that all should pray that they may have a sound mind in a sound body.

9. Our bodies are preserved in health and strength by a regular and moderate life, and on this we will make a few remarks from the medical point of view, taking a tree as illustration. In order to maintain its freshness, a tree needs three things: (1) a continuous supply of moisture; (2) copious transpiration; (3) an alternating period of rest and activity.

Moisture is necessary, because the tree would wither and dry up without it, but it must not be supplied in too great a quantity, as, if it be, it causes the roots to rot away. In the same way the body needs nourishment, because it wastes away from hunger and thirst without it; but it should not obtain a supply so large that the stomach is unable to digest it. The greater the moderation with which men partake of food, the easier they find its digestion.

The generality of men pay but little attention to this law, and by taking too much food diminish their strength and shorten their lives. For death is caused by disease, disease by unwholesome juices, and these, in turn, by insufficient digestion. Insufficient digestion arises from over-nutrition, and takes place when the stomach is so full that it cannot digest, and is compelled to supply the various members of the body with semi-digested juices, and in this case it is impossible that diseases should not arise. As the son of Sirach says: “By surfeiting have many perished, but he that taketh heed prolongeth his life” (Ecclesiasticus xxxvii. 31).

10. In order that good health may be preserved, it is necessary that nourishment be not only moderate in quantity, but also simple in quality. When a tree is young and tender, the gardener does not water it with wine or with milk, but with the liquid that suits trees, namely water. Parents should therefore take care not to spoil their boys, particularly those who study, or ought to study,