Nor must it be forgotten that there is nothing in Heraclitus analogous to the reasoning forms of the Stoics, nor can their ethical views be referred to his few and undeveloped hints. With all the importance the Stoics attached to natural science, it is with them only subordinate to moral science; and the very fact that it is referred to Heraclitus as its author, proves its inferior position, and the want of any independent interest in the subject. It is also unmistakeable that even in natural science the Stoics only partially follow Heraclitus, and that principles taken from Heraclitus often bear an altered meaning when wrought into the Stoic system. Omitting minor points, not only is the Stoic doctrine of nature in a formal point of view far more developed, and with regard to its extension far more comprehensive, than the corresponding doctrine of Heraclitus, but the whole Stoic view of the world is by no means so completely identical with his as might be supposed. The flux of things, which the Stoics teach equally with Heraclitus, [1042] has not for them that overwhelming importance that it had for him. The matter of which the universe consists may be always going over into new forms, but, at the same time, it is for them the permanent material and essence of things. [1043] Individual substances, too, are treated by the Stoics as corporeally permanent. [1044] Moreover, from the material they distinguish the active principle, Reason or deity, far more definitely than Heraclitus had done, and the same distinction is carried into individual things in the contrast between matter and quality. Thereby it becomes possible for them to contrast much more sharply than their predecessor had done the reason of the world, and the blindly working power of nature. Heraclitus, it would appear, confined his attention to observing nature and describing its elementary meteorological processes. But the natural science of the Stoics includes the idea of means working for ends. It sees the object in referring the whole arrangement of the world to man, and it pursues this line of thought exclusively, neglecting in consequence science proper. Hence the idea of sovereign reason or the universal law had not the same meaning in the minds of both. Heraclitus sees this reason, primarily and chiefly, in the ordinary sequence of natural phenomena, in the regularity of the course by which to each individual phenomenon its place in the world, its extent and duration are prescribed—in short, in the unchanging coherence of nature. Without excluding this aspect in their proofs of the existence of God and the rule of Providence, the Stoics attach the chief importance to the serviceableness of the order of nature. The reason which rules the world appears in Heraclitus primarily as a natural power; in the Stoics, as intelligence working with a purpose. For Heraclitus Nature is the highest object, the object of independent and absolute interest;