=5.= Among the Greeks ethical philosophy began with Socrates. Their earlier writers dealt with the subject of duty but little in a speculative way. When the philosophy of it came to be sought the theories mainly connected it closely with "the good" or "the highest good," the _summum bonum_ of life. This designation was ambiguous. "The good" (τὸ ἀγαθόν, τὰ ἀγαθά [Greek: to agathon], [Greek: ta agatha]) might be conceived of as either intellectual or sensuous good, as consisting in one's intrinsic state or in outward condition, as either happiness or personal well-being. And because this method failed to distinguish clearly and fully between this indefinite "good"--having at best no more authority than "the beautiful"--and "the right" which forms the true essence of the ethical principle, their explanations failed to become clear, and stopped short of being actual explanations of the ground of right. Hence their theories, though not always consistently exhibited, and variously interpreted by expounders of them, were substantially _eudæmonistic_[43] and _utilitarian_. Specifically: (1) Socrates made all virtue consist in knowledge, especially self knowledge or wisdom, leading men to proper self-regulation and happiness. He put emphasis upon man's rational nature as essentially good, and to this rational nature belonged the office of self-mastery and control of all appetites, dispositions, and passions. The life in knowledge became the good and happy life. Though this great sage maintained that the world is governed by a supreme intelligence, he failed to connect clearly and closely the moral law with this high source, and rested the moral life simply subjectively. (2) Plato developed his view substantially on the basis of that of Socrates. He identified the highest good with the intellect rather than the sensibility, and looked upon all virtues as united in _knowledge_, not only as guiding the soul in acting out its proper destination, but, according to some statements, even as in itself all-sufficing. Though Plato's speculative view of the universe contains the elements for the construction of a sublime immutable ethical standard, and he even suggests God-likeness as the goal of man's moral life,[44] the implications of his view are not consistently carried out; and when he comes to apply his ideas to life in his ideal Republic he lapses into what seems a caricature of his better thought, and is content to rest morality simply on the authority and laws of the state.[45]