It’s been observed many times but, I think, never so well and sumptuously:
To say truth, nothing is more erroneous than the common observation, that men who are ill-natured and quarrelsome when they are drunk, are very worthy persons when they are sober: for drink, in reality, doth not reverse nature, or create passions in men which did not exist in them before. It takes away the guard of reason, and consequently forces us to produce those symptoms, which many, when sober, have art enough to conceal. It heightens and inflames our passions (generally, indeed, that passion which is uppermost in our minds), so that the angry temper, the amorous, the generous, the good-humored, the avaricious, and all other dispositions of men, are in their cups heightened and exposed.
–From Tom Jones, by Henry Fielding