There are other possible definitions of pessimism, and it is hard to arbitrate between pessimistic and optimistic attitudes, first because these tend to be vague, imprecize and general positions anyway, and second because they seem to depend rather a lot on one's native temperament, and some are born melancholic, and others happy-go-lucky, both with little choice, other than medication.

Even so, two things can be said on the side of pessimism as a practical attitude, after reiterating that one cannot be precize here, and stressing that real melancholia and depression are medical conditions, that are excluded here.

First, in many practical things it is wise not to be overly optimistic about one's chances of success. This both prevents grave disappointments (which can make one very much more pessimistic than the - so to speak - academic pessimism in practical matters recommended here) and counsels to properly investigate one's chances of failure, in order to counter them, and not to enter into prospects that have a small chance of success, especially if the price of failure is large.

This is not always wise, because if one takes action, it usually is better to do it in a committed and fullhearted way. But it is wise when one deliberates about what one can and might desire to do, if one has that freedom - which one does not always have. But then, if one can, the rule of thumb seems: Be pessimistic in your estimates, but optimistic in your acts - deliberate carefully, but do boldly, for you can choose from many, but select and do just one.

And indeed, there are conditions, such as dictatorship and persecution, that one has little choice to resist, whatever the chances of success and the price of failure, unless one wishes to commit suicide or be a conformist, coward and collaborator.

Second, in many theoretical and especially ideological things it is wise not to be too much of a credulous idealist about human beings: Much of the harm men do - and men have done very much harm in history - is based on idealism and founded on faith in rationally incredible doctrines and promises (such as the Millenium, God's blessings in war, or 72 heavenly virgins for eternity, for martyrs of the faith).

In brief: Since the worst things have been done for the noblest sounding reasons, it makes sense to remember that 'men incline much to evil, and little to good', even if that may not be true of all men or women.