It would appear that even in the Pythagorean school there had been a reaction against a doctrine which its founder had been the first to popularise in Hellas. The Pythagoreans had always attributed great importance to the conceptions of harmony and numerical proportion; and they soon came to think of the soul as a ratio which the different elements of the animal body bore to one another; or as a musical concord resulting from the joint action of its various members, which might be compared to the strings of a lute. But ‘When the lute is broken Sweet tones are remembered not.’ And so, with the dissolution of our bodily organism, the music of consciousness would pass away for ever. Perhaps no form of psychology taught in the Greek schools has approached nearer to modern thought than this. It was professed at Thebes by two Pythagoreans, Cebes and Simmias, in the time of Plato. He rightly regarded them as formidable opponents, for they were ready to grant whatever he claimed for the soul in the way of immateriality and superiority to the body, while denying the possibility of its separate existence. We may so far anticipate the course of our exposition as to mention that the direct argument by which he met them was a reference to the moving power of mind, and to the constraint exercised by reason over passionate impulse; characteristics which the analogy with a musical harmony failed to explain. But his chief reliance was on an order of considerations, the historical genesis of which we shall now proceed to trace.