"A combination composed of a sacrifice has more immediate effect upon the person playing over the game in which it occurs than another combination, because the apparent senselessness of the sacrifice is convincing proof of the design of the player offering it. Hence it comes that the risk of material, and the victory of the weaker material over the stronger material, gives the impression of a symbol of the mastery of mind over matter.
Now we see wherein lies the pleasure to be derived from a chess combination. It lies in the feeling that a human mind is behind the game dominating the inanimate pieces with which the game is carried on, and giving them the breath of life. We may regard it as an intellectual delight, equal to that afforded us by the knowledge that behind so many apparently disconnected and seemingly chance happenings in the physical world lies the one great ruling spirit - the law of Nature. "


a quote from Richard Reti, Modern Ideas in Chess, found at the super useful Exeter Chess Club site, http://www.ex.ac.uk