The paper discusses three basic concepts of nature of morality, formed in the history of ethical thought: religious, naturalistic and socio-historical. The religious concept has come from the assumption that moral values and norms, concepts of the good and evil, as well as a person’s ability to follow them, are given to him by God. Naturalistic concept, as opposed to religious one, displays moral values and demands as derived from nature in general and of human nature as its part. As for the socio- historical concept, according to it, morality originates from the public need for mutual coordination, regulation and integration in public life. The author analyzes the advantages and disadvantages of each of these concepts and relates them to three world political ideologies: conservatism, liberalism and socialism. The author has concluded that none of the ways to justify the nature of morality proves its necessity. Nevertheless, they all demonstrate certain logics of philosophical, political and moral thought, contain important substantial arguments to prove the need for ethical behavior in the interests of an individual, the public and the state.