On the other hand Epicurus and Zeno agreed both in their aim of rationally explaining the nature of things, and in their physiological method, which set out from the conception of matter.

They diverged, in so far as Epicurus, following the atomic theory of Democritus, conceived the first principle as rigid matter, and evolved the manifoldness of things out of this matter merely by mechanical variations; whereas Zeno, forming his views after the Ephesian Heraclitus, introduces even into his primordial matter a dynamic antagonism and a movement of fluctuation up and down.

From this are derived the further distinctions--that in the Epicurean system the gods as it were did not exist or were at the most a dream of dreams, while the Stoical gods formed the ever-active soul of the world, and were as spirit, as sun, as God powerful over the body, the earth, and nature; that Epicurus did not, while Zeno did, recognize a government of the world and a personal immortality of the soul; that the proper object of human aspiration was according to Epicurus an absolute equilibrium disturbed neither by bodily desire nor by mental conflict, while it was according to Zeno a manly activity always increased by the constant antagonistic efforts of the mind and body, and striving after a harmony with nature perpetually in conflict and perpetually at peace.

But in one point all these schools were agreed with reference to religion, that faith as such was nothing, and had necessarily to be supplemented by reflection-- whether this reflection might consciously despair of attaining any result, as did the Academy; or might reject the conceptions of the popular faith, as did the school of Epicurus; or might partly retain them with explanation of the reasons for doing so, and partly modify them, as did the Stoics.
Carneades at Rome It was accordingly only a natural result, that the first contact of Hellenic philosophy with the Roman nation equally firm in faith and adverse to speculation should be of a thoroughly hostile character.
The Roman religion was entirely right in disdaining alike the assaults and the reasoned support of these philosophical systems, both of which did away with its proper character.

The Roman state, which instinctively felt itself assailed when religion was attacked, reasonably assumed towards the philosophers the attitude which a fortress assumes towards the spies of the army advancing to besiege it, and as early as 593 dismissed the Greek philosophers along with the rhetoricians from Rome.