Now in this aim, we must ask, does a man need other men and other creatures, and in what sense does he need them? Here, I think, we come on two inconsistent tendencies in Aristotle's thought, connected with two different ways of regarding the hierarchy of existences. We say that one existence is higher than another. Does this mean that what we call the lower are only so many blundering attempts to reach the higher? That every creature, for example, which is not a thinking man is, on the whole, a mistake? Aristotle often does speak like that. Woman, he says in one passage, is only a mutilated male.[22] The principle which ought to develop into the active power of thought could not, he explains, in women master the recalcitrant element which is always thwarting perfection, and thus woman is man _manque_. On these lines of thought it is easy to slip into looking on all other forms of existence as merely valuable in so far as they serve the direct purposes of men, and indeed only of a few men, those namely who are able to think as philosophers. This is the kind of view according to which, as the satirist suggests, cork-trees only grow in order to make corks for champagne-bottles, and the inferior races of mankind only exist to furnish slaves for the higher. And Aristotle does, on occasion, lend himself to such a view: he justifies a slavery in which, as he says, some men are to be treated merely as living tools. And yet on his own principles every man ought to aim at realizing his own end, and not merely the ends of others.