The most authentic witnesses of any man’s character are those who know him in his own family, and see him without any restraint or rule of conduct, but such as he voluntarily prescribes to himself. If a man carries virtue with him into his private apartments, and takes no advantage of unlimited power or probable secrecy; if we trace him through the round of time, and find that his character, with those allowances which mortal frailty must always want, is uniform and regular, we have all the evidence of his sincerity that one man can have with regard to another; and, indeed, as hypocrisy cannot be its own reward, we may, without hesitation, determine that his heart is pure —Johnson (Rambler, No. 68).
Dostoyevsky once remarked that a Russian peasant may “abandon everything and go off to Jerusalem on a pilgrimage. Or he may suddenly set fire to his native village. Or he may do both.” Such caprice is a theme that runs through many of his stories and is what lies at the heart of his great villains and sinners. Nor am I sure that it is terribly reassuring—whether in novels or in real life—that impulsive people can sometimes be exceptionally generous and good. The problem is that when virtue is spontaneous, so is vice, and even good behavior becomes unpredictable.
A person should above all be dependable. For example when it comes to parenting, the experts can at least agree that consistency is often more important than other qualities. It builds trust, which is a prerequisite for happiness. On the other hand we see what happens when people cannot control their feelings. The most immediate damage takes place in the family (though it invariably spills over into society as well).
In urging even-temperedness, Johnson noted that
A thousand miseries make silent and invisible inroads on mankind, and the heart feels innumerable throbs, which never break into complaint. Perhaps, likewise, our pleasures are for the most part equally secret, and most are borne up by some private satisfaction, some internal consciousness, some latent hope, some peculiar prospect, which they never communicate, but reserve for solitary hours and clandestine meditation (ibid.).
I can only repeat the old advice that it is not how we handle those rare big crises in life, but how we react to innumerable lesser annoyances, distractions or pleasures, without ostentation or self-indulgence, that marks our true character. The greater restraint we place on our emotions the more they reveal depth of feeling when we do indulge them.