Excerpt from The Art of Worldly Wisdom by Baltasar Gracián.

ccxxiv Never take Things against the Grain,

no matter how they come. Everything has a smooth and a seamy side, and the best weapon wounds if taken by the blade, while the enemy's spear may be our best protection if taken by the staff. Many things cause pain which would cause pleasure if you regarded their advantages. There is a favourable and an unfavourable side to everything, the cleverness consists in finding out the favourable. The same thing looks quite different in another light; look at it therefore on its best side and do not exchange good for evil. Thus it haps that many find joy, many grief, in everything. This remark is a great protection against the frowns of fortune, and a weighty rule of life for all times and all conditions.