The chief point, however, to which Plato directed his attention, was ethics, which, especially in his system, are closely connected with politics. He devotes the Protagoras, and several shorter dialogues, to refute the sensual and selfish theories of some of his predecessors, in order to adopt a more scientific treatment of the subject; and in these dialogues he urges that neither happiness nor virtue are attainable by the indulgence of our desires, but that men must bring these into proper restraint, if they are desirous of either. He supposes an inward harmony, the preservation of which is pleasure, while its disturbance is pain; and as pleasure is always dependent on the activity from which it springs, the more this activity is elevated the purer the pleasure becomes. Virtue he considered the fitness of the soul for the operations that are proper to it; and it manifests itself by means of its inward harmony, beauty, and health. Different phases of virtue are distinguishable so far as the soul is not pure spirit, but just as the spirit should rule both the other elements of the soul, so also should wisdom, as the inner development of the spirit, rule the other virtues. Politics he considered an inseparable part of ethics, and the state as the copy of a well-regulated individual life: from the three different activities of the soul he deduced the three main elements of the state, likening the working class to the appetitive element of the soul, both of which equally require to be kept under control; the military order, which answered, in his idea, to the emotive element, ought to develop itself in thorough dependence on the reason; and from that the governing order, answering to the rational faculty, must proceed. The right of passing from a subordinate to a dominant position must depend on the individual capacity and ability for raising itself. But from the difficulties of realizing his theories, he renounces this absolute separation of ranks in his book on Laws, limits the power of the governors, attempts to reconcile freedom with unity and reason, and to mingle monarchy with democracy. With respect to his theology, he appears to have agreed entirely with Socrates.