Weak points or holes in the opponent's position must be occupied by pieces not Pawns
Siegbert TarraschA form of intellectual productiveness, therein lies its peculiar charm. Intellectual productiveness is one of the greatest joys - if not the greatest one - of human existence. It is not everyone who can write a play, or build a bridge, or even make a good joke. But in chess everyone can, everyone must be intellectually productive, and so can share in this select delight. I have always a slight feeling of pity for the man who has no knowledge of chess, just as I would pity the man who has remained ignorant of love. Chess, like love, like music, has the power to make men happy.
Siegbert Tarrasch