ONE:"But you have no Jill," she said, smiling at Ellton. His own smile was very strained, but she did not see that, nor the shade of trouble in his nice blue eyes. TWO:It cannot be too often repeated that the One in no way conflicts with the world of real existence, but, on the contrary, creates and completes it. Now, within that world, with which alone reason is properly concerned, Plotinus never betrays any want of confidence in its power to discover truth; nor, contrary to what Zeller assumes, does he seem to have been in the least affected by the efforts of the later Sceptics to invalidate its pretensions in this respect.508 Their criticism was, in fact, chiefly directed against Stoicism, and did not touch the spiritualistic position at all. That there can be no certain knowledge afforded by sensation, or, speaking more generally, by the action of an outward object on an inward subject, Plotinus himself fully admits or rather contends.509 But while distrusting the ability of external perception, taken alone, to establish the existence of an external object by which it is caused, he expressly claims such a power for reason or understanding.510 For him, as for Aristotle, and probably for Plato also, the mind is one with its real object; in every act of cognition the idea becomes conscious of itself. We do not say that Scepticism is powerless against such a theory as this, but, in point of fact, it was a theory which the ancient Sceptics had not attacked, and their arguments no more led Plotinus to despair of reason, than the similar arguments of Protagoras and Gorgias had led Plato and Aristotle to despair of it six centuries before. If Sextus and his school contributed anything to the great philosophical revolution of the succeeding age, it was by so344 weakening the materialistic systems as to render them less capable of opposing the spiritualistic revival when it came.