Again, I think that Zeller quite misconceives the relation between Greek philosophy and Greek life when he attributes the intellectual decline of the post-Aristotelian period, in part at least, to the simultaneous ruin of public spirit and political independence. The degeneracy of poetry and art, of eloquence and history, may perhaps be accounted for in this way, but not the relaxation of philosophical activity. On the contrary, the disappearance of political interests was of all conditions the most favourable to speculation, as witness the Ionians, Democritus, and Aristotle. Had the independence and power of the great city-republics been prolonged much further, it is probable--as the example of the Sophists and Socrates seems to show--that philosophy would have become still more absorbingly moral and practical than it actually became in the Stoic, Epicurean, and Sceptical schools. And theoretical studies did, in fact, receive a great impulse from the Macedonian conquest, a large fund of intellectual energy being diverted from public affairs to the pursuit of knowledge, only it took the direction of positive science rather than of general speculation.[2] The cause which first arrested and finally destroyed the free movement of Greek thought was not any intrinsic limitation or corruption of the Greek genius, but the ever-increasing preponderance of two interests, both tending, although in different ways and different degrees, to strengthen the principle of authority and to enfeeble the principle of reason. One was the theological interest, the other was the scholastic interest. The former was the more conspicuous and the more mischievous of the two. From the persecution of Anaxagoras to the prohibition of philosophical teaching by Justinian, we may trace the rise and spread of a reaction towards superstition, sometimes advancing and sometimes receding, but, on the whole, gaining ground from age to age, until from the noontide splendour of Pericles we pass to that long night which stretches in almost impenetrable darkness down to the red and stormy daybreak of the Crusades. And it was a reaction which extended through all classes, including the philosophers themselves. It seems to me that where the Athenian school, from Socrates on, fall short of their predecessors, as in some points they unquestionably do, their inferiority is largely due to this cause. Its influence is very perceptible in weakening the speculative energies of those who stand at the greatest distance from the popular beliefs. It was because dislike for theology occupied so large a place in the thoughts of Epicurus and his disciples, that they valued science only as a refutation of its teaching, instead of regarding it simply as an obstacle to be removed from the path of enquiry. More than this; they became infected with the spirit of that against which they fought, and their absolute indifference to truth was the shadow which it cast on their minds.