A cold air constringes the extremities of the external fibers of the body; this increases their elasticity, and favors the return of the blood from the extreme parts to the heart. It contracts those very fibers; consequently it increases also their force. On the contrary, a warm air relaxes and lengthens the extremes of the fibers; of course it diminishes their force and elasticity. People are therefore more vigorous in cold climates. Here the action of the heart and the reaction of the extremities of the fibers are better performed, the temperature of the humors is greater, the blood moves freer toward the heart, and reciprocally the heart has more power. This superiority of strength must produce various effects; for instance, a greater boldness--that is, more courage; a greater sense of superiority--that is, less desire of revenge; a greater opinion of security--that is, more frankness, less suspicion, policy, and cunning. In short, this must be productive of very different tempers. Put a man into a close, warm place, and for the reasons above given he will feel a great faintness. If under this circumstance you propose a bold enterprise to him, I believe you will find him very little disposed towards it; his present weakness will throw him into a despondency; he will be afraid of every thing, being in a state of total incapacity. The inhabitants of warm countries are, like old men, timorous; the people in cold countries are, like young men, brave. In the following extract, from chapter five, Book XXIV., the climatic theory is again applied, this time to the matter of religion, in a style that makes one think of Buckle's "History of Civilization": When the Christian religion, two centuries ago, became unhappily divided into Catholic and Protestant, the people of the north embraced the Protestant, and those south adhered still to the Catholic. The reason is plain: the people of the north have, and will forever have, a spirit of liberty and independence, which the people of the south have not; and therefore a religion which has no visible head is more agreeable to the independency of the climate than that which has one. Climate is a "great matter" with Montesquieu. In treating of the subject of a State changing its religion, he says: The ancient religion is connected with the constitution of the kingdom, and the new one is not; the former _agrees with the climate_, and very often the new one is opposite to it.