Among the things about himself that man has understood poorly are the effects of his behavior on the prospects for his continuing existence. If humans fail to find answers to the problem of their behavioral-ecological relationships and to be guided by this knowledge, their future may be too brief to find answers to most of the other perplexing questions about human behavior. Only recently have humans found means to discover the true nature of their ecological situation; and only recently has it become imperative to assess these findings correctly and to act upon their implications while there is yet time for choice. For human society is now at one of the critical stages in its evolution, and whether it can surmount it and move to a “higher” level of existence is conjectural.