This is the second of a series of papers on the problem of suicide, in the first of which the author stated that he believed suicide to be 'the most profound pathologic process in the field of psychology'. The differences of opinion whether or not all persons committing suicide are psychotic depends on the definition of 'insanity'.

The term 'adaptation' is taken to mean those forces tending toward the 'preservation of organic unity' expressed at the chemical, physical and psychological levels. The two implied factors, individual and environment, are actually inseparable if the individual is to continue to exist. Adaptive processes must remain plastic to survive or to avoid competition. In the human organism the 'higher' functions have become adapted