Zeno is said to have been the most remarkable of this school. He held that if there was a distinction between _being_ and _not being_, only _being_ existed. This led him to the final assumption that the laws of nature are unchangeable and God remains permanent. His method of reasoning was to reduce the opposite to absurdity. Upon the whole, the Eleatic philosophy is one relating to knowledge and being, which considered thought primarily as dependent upon being. It holds closely to monism, that is, that nature and mind are of the same substance; yet there is a slight distinction, for there is really a dualism expressed in knowledge and being. Many other philosophers followed, who discoursed upon nature, mind, and being, but they arrived at no definite conclusions. The central idea in the early philosophy up to this time was to account for the existence and substance of nature. It gave little consideration to man in himself, and said little of the supernatural. Everything was speculative in nature, hypothetical in proposition, and deductive in argument. The Greek mind, departing from its dependence upon mythology, began boldly to assert its ability to find out nature, but ended in a scepticism as to its power to ascertain certainty. There was a final determination as to the distinction of reality as external to mind, and this represents the best product of the early philosophers. {221} _The Sophists_.--Following the Eleatics was a group of philosophers whose principle characteristic was scepticism. Man, not nature, was the central idea in their philosophy, and they changed the point of view from objective to subjective contemplation. They accomplished very little in their speculation except to shift the entire attitude of philosophy from external nature to man. They were interested in the culture of the individual, yet, in their psychological treatment of man, they relied entirely upon sense perception. In the consideration of man's ethical nature they were individualistic, considering private right and private judgment the standards of truth. They led the way to greater speculation in this subject and to a higher philosophy.