And it should be borne in mind that, in their intercourse with others, people are like the moon, or like hunchbacks; they show you only one of their sides.  Every man has an innate talent for mimicry,—­for making a mask out of his physiognomy, so that he can always look as if he really were what he pretends to be; and since he makes his calculations always within the lines of his individual nature, the appearance he puts on suits him to a nicety, and its effect is extremely deceptive.  He dons his mask whenever his object is to flatter himself into some one’s good opinion; and you may pay just as much attention to it as if it were made of wax or cardboard, never forgetting that excellent Italian proverb:  non e si tristo cane che non meni la coda,—­there is no dog so bad but that he will wag his tail.

In any case it is well to take care not to form a highly favorable opinion of a person whose acquaintance you have only recently made, for otherwise you are very likely to be disappointed; and then you will be ashamed of yourself and perhaps even suffer some injury.  And while I am on the subject, there is another fact that deserves mention.  It is this.  A man shows his character just in the way in which he deals with trifles,—­for then he is off his guard.  This will often afford a good opportunity of observing the boundless egoism of man’s nature, and his total lack of consideration for others; and if these defects show themselves in small things, or merely in his general demeanor, you will find that they also underlie his action in matters of importance, although he may disguise the fact.  This is an opportunity which should not be missed.  If in the little affairs of every day,—­the trifles of life, those matters to which the rule de minimis non applies,—­a man is inconsiderate and seeks only what is advantageous or convenient to himself, to the prejudice of others’ rights; if he appropriates to himself that which belongs to all alike, you may be sure there is no justice in his heart, and that he would be a scoundrel on a wholesale scale, only that law and compulsion bind his hands.  Do not trust him beyond your door.  He who is not afraid to break the laws of his own private circle, will break those of the State when he can do so with impunity.

If the average man were so constituted that the good in him outweighed the bad, it would be more advisable to rely upon his sense of justice, fairness, gratitude, fidelity, love or compassion, than to work upon his fears; but as the contrary is the case, and it is the bad that outweighs the good, the opposite course is the more prudent one.