310 PHYSICAL SCIENCE IN THE MIDDLE AGES. 



universally and powerfully during the stationary 

 period, its existence, even as a detailed technical 

 system, goes back to a very early age. It pro- 

 bably had its origin in the East; it is universally 

 ascribed to the Babylonians and Chaldeans; the 

 name Chaldean was, at Rome, synonymous with 

 mathematicus, or astrologer; and we read repeat- 

 edly that this class of persons were expelled from 

 Italy by a decree of the senate, both during the 

 times of the republic and of the empire 14 . The 

 recurrence of this act of legislation shows that it 

 was not effectual ; " It is a class of men," says 

 Tacitus, "which, in our city, will always be pro- 

 hibited, and will always exist." In Greece, it does 

 not appear that the state showed any hostility to 

 the professors of this art. They undertook, it 

 would seem, then, as at a later period, to determine 

 the course of a man's character and life from the 

 configuration of the stars at the moment of his 

 birth. We do not possess any of the speculations 

 of the earlier astrologers ; and we cannot therefore 

 be certain that the notions which operated in men's 

 minds when the art had its birth, agreed with the 

 views on which it was afterwards defended, when 

 it became a matter of controversy. But it ap- 

 pears probable, that, though it was at later periods 

 supported by physical analogies, it was originally 

 suggested by mythological belief. The Greeks 

 spoke of the influences or effluxes (airoppoias) which 

 14 Tacit. Ann. ii. 32. xii. 52. ///*/. I. 22, II. 62. 



