This book is the compilation of three different lectures given by Vlissidis in Parnassos in 1932, in the School of the University of Athens in 1933 and in the Lyceum of Greek Women. The book starts by discussing the relations of Marxism and Darwinism, goes on to describe the ramification of the 'struggle for existence' in a society and ends by offering some views on how society can be structured according to the needs of human nature.