In The German Ideology he uses the formulation: 'their needs, consequently their nature' . We can see then, that from Marx's early writing to his later work, he conceives of human nature as composed of 'tendencies', 'drives', 'essential powers', and 'instincts' to act in order to satisfy 'needs' for external objectives. For Marx then, an explanation of human nature is an explanation of the needs of humans, together with the assertion that they will act to fulfill those needs. (c.f.