Happiness is to know how always to choose the mean and shun the excess in either direction

. . . know how always to choose in such things the life that is seated in the mean and shun the excess in either direction, both in this world so far as may be and in all the life to come; for this is the greatest happiness for man.

-- Plato, Republic, Book X, 619

Happiness is new research which may explain why small amounts of alcohol are heart healthy

"Shun the excess in either direction" Republic 10.619a

From the story here:

In tests on mice's hearts researchers interrupted the flow of oxygen and nutrients to the heart for 30 minutes to simulate myocardial infarction – a heart attack. This was less damaging for hearts which had been exposed to alcohol, they found. Some 50 per cent of cells died during the heart attack in the hearts which was not exposed to alcohol. However, in the hearts that had been exposed to the equivalent of two cans of beer or two glasses of wine for an average man, only 30 per cent of cells died. 'Our data suggest moderate exposure to ethanol causes minor stress in heart cells but not enough to kill them,' says Professor Julio Cesar Batista Ferreira. 'Heart cells eventually create a biochemical memory to protect against stress, also known as preconditioning. 'When the cells are submitted to a higher level of stress, they know how to deal with it.'