In the Ethics Spinoza offers us a model of the good life that we can use as a measure of human perfection; living well consists in conducting our lives as far as possible on the basis of a correct grasp of the abilities and weaknesses of human beings, together with a true understanding of the world they inhabit. A person who achieves this form of existence becomes what Spinoza calls a free man, who lives 'according to the dictate of reason alone' (4pref). Although this ideal consists in the possession of reason or understanding, it is also characterised by the absence of something that Spinoza regards as an imperfection, namely the dominance of affects or passions, whether negative ones such as envy and hatred or their positive counterparts such as love and joy. The passions are therefore viewed as obstacles to freedom, and as long as we are unable to control and transcend them there is a sense in which we are enslaved. 'Man's lack of power to moderate and restrain the affects I call Bondage [servitus]. For the man who is subject to affects is under the control, not of himself, but of fortune, in whose power he so greatly is that often, though he sees the better for himself, he is still forced to follow the worse' (4pref). Correspondingly, only insofar as we counteract our passions can we be said to be free. In defending this alignment of reason with liberty and passion with slavery Spinoza is reiterating an outlook at least as old as Plato, for whom the mind is like a chariot pulled by two horses, one biddable and the other unruly (Plato 1997, 530-33, 253c-7).