A living creature develops a destructive impulse when it wants to destroy a source of danger. In this case, the destruction or killing of the object is the biologically purposeful goal. The original motive is not pleasure in destruction. Rather the destruction serves the "life instinct"... and is an attempt to avoid anxiety and to preserve the ego in its totality. I destroy in a dangerous situation because I want to live and do not want to have any anxiety. In short, the impulse to destroy serves a primary biological will to live...

Ch. V : The Development of the Character-Analytic Technique - The Function of the Orgasm (1927)