 on aggress in book lorenz deal evolut aggress vertebr he point aggress total predat biolog necess defenc territori corner anim mix innat drive lead reduct intraspecif damag thi evid fiercer social predat wolv escap pack virtual imposs co-oper fight surviv non-social proverbi peac dove prevent escap lead violent fatal attack weaker mate in final chapter advanc suggest human speci evolut cultur guid darwinian select strict sens aggress drive canal danger channel man innumer wai adapt ritual behavior analog homolog anim in event on aggress fascin book master subject 