Our ideas of what sort of progress is possible or desirable for man depend, part at least, upon our views of his biological nature. Thus, the study of biology is necessary for a study of sociology. It is not possible to determine the modes and limits of man’s social progress without being acquainted with man’s physical capacities, qualities and limitation.

Biology presents us with this very knowledge. It studies man’s origin and biological development describes his development-sexual, analomical and personal and formulates principles for his adjustment to the environment. Darwinian Theory of evolution is just one such principle which has been used in sociology to good advantage. Human ecology is based upon biological ecology.

Genetics, which is of major importance in sociology, is a branch of biology. Sociologists have taken a lot of assistance from it in connection with the improvement of species of breed. In sociology knowledge of the effects of heredity upon man is also much needed? That is studied by biology. In sociology, the influence of biology upon the organic theory of society is very clear and evident. Knowledge of biology is essential for sociology when the problems stud ied are concerned with marriage and family.

But biological principles can be applied in the social sphere only up to certain limits. Indiscriminate application beyond these limits can lead to drastic consequences.