In what way, then, can the two facts be combined—the belief in prophecy, on the one hand, and, on the other, the denial of unearthly omens arising [(2) Prophecy explained by a reference to natural causes.] from an immediate divine influence? In answering this question, the Stoics adopted the only course which their system allowed. The marvellous, which, as such, they could not admit, was referred to natural laws, [1003] from which it was speculatively deduced. The admirable Panætius is the only Stoic who is reported to have maintained the independence of his judgment by denying omens, prophecy, and astrology. [1004] Just as in modern times Leibnitz and so many others both before and after him thought to purge away from the marvellous all that is accidental and superhuman, and to find in wonders links in the general chain of natural causes, so, too, the Stoics, by assuming a natural connection between the token and its fulfilment, made an effort to rescue omens and divination, and to explain portents as the natural symptoms of certain occurrences. [1005] Nor did they confine themselves to cases in which the connection between the prophecy and the event can be proved. [1006] They insisted upon divination in cases in which it cannot possibly be verified. The flight of birds and the entrails of victims are stated to be natural indications of coming events; and there is said to be even a formal connection between the positions of the stars and the individuals born under those positions. [1007] If it is urged, that in this case omens must be far more numerous than they are supposed to be, the Stoics answered, that omens are countless, but that only the meaning of a few is known to men. [1008] If the question is asked, how is it that, in public sacrifices, the priest should always offer those very animals whose entrails contain omens, Chrysippus and his followers did not hesitate to affirm that the same sympathy which exists between objects and omens also guides the sacrificer in the choice of a victim. [1009] And yet so bald was this hypothesis, that they had, at the same time, a second answer in reserve, viz. that the corresponding change in the entrails did not take place until the victim had been chosen. [1010] In support of such views, their only appeal was to the almighty power of God; but, in making this appeal, the deduction of omens from natural causes was at an end. [1011] The Stoics could not altogether suppress a suspicion that an unchangeable predestination of all events has rendered individual activity superfluous, [1012] nor meet the objection [1013] that, on the hypothesis of necessity, divination itself is unnecessary. [1014] They quieted themselves, however, with the thought that divination, and the actions resulting from divination, are included among the causes foreordained by destiny. [1015] [(3) Causes of divination.]