Human actions are determined by the needs deriving from man's nature and from the natural and social environment in which man moves. For man's nature to appear in all its fullness, with all his aspirations and needs, man should not be viewed as isolated as neither nature nor life isolates him, for it is to isolate him from destroying his flesh. Man must be seen in the midst of other people, in constant and necessary contact with them. Man does not become man but in contact with other people. Contact with other people appears as a necessary condition of human life; a Robinson will not live as a human, unless there is a reminder of his contact with other people and the hope of finding them; with the extinction of the last hope and the last memory will disappear its being.