BOOK THE FIRST
CHAPTER I
PROEM
The studies preliminary to astronomical prognostication, O Syrus! are two: the one, first alike in order and in power, leads to the knowledge of the figurations of the Sun, the Moon, and the stars; and of their relative aspects to each other, and to the earth: the other takes into consideration the changes which their aspects create, by means of their natural properties, in objects under their influence.
The first mentioned study has been already explained in the Syntaxis[19] to the utmost practicable extent; for it is complete in itself, and of essential utility even without being blended with the second; to which this treatise will be devoted, and which is not equally self-complete. The present work shall, however, be regulated by that due regard for truth which philosophy demands: and since the material quality of the objects acted upon renders them weak and variable, and difficult to be accurately apprehended, no positive or infallible rules (as were given in detailing the first doctrine, which is always governed by the same immutable laws) can be here set forth: while, on the other hand, a due observation of most of those general events, which evidently trace their causes to the Ambient, shall not be omitted.
It is, however, a common practice with the vulgar to slander everything which is difficult of attainment, and surely they who condemn the first of these two studies must be considered totally blind, whatever arguments may be produced in support of those who impugn the second. There are also persons who imagine that whatever they themselves have not been able to acquire, must be utterly beyond the reach of all understanding; while others again will consider as useless any science of which (although they may have been often instructed in it) they have failed to preserve the recollection, owing to its difficulty of retention. In reference to these opinions, therefore, an endeavour shall be made to investigate the extent to which prognostication by astronomy is practicable, as well as serviceable, previously to detailing the particulars of the doctrine.
CHAPTER II
KNOWLEDGE MAY BE ACQUIRED BY
ASTRONOMY TO A CERTAIN EXTENT
That a certain power, derived from the æthereal nature, is diffused over and pervades the whole atmosphere of the earth, is clearly evident to all men. Fire and air, the first of the sublunary elements, are encompassed and altered by the motions of the æther. These elements in their turn encompass all inferior matter, and vary it as they themselves are varied; acting on earth and water, on plants and animals.[20]
The Sun, always acting in connection with the Ambient, contributes to the regulation of all earthly things: not only by the revolution of the seasons does he bring to perfection the embryo of animals, the buds of plants, the spring of waters, and the alteration of bodies, but by his daily progress also he operates other changes in light, heat, moisture, dryness and cold; dependent upon his situation with regard to the zenith.
The Moon, being of all the heavenly bodies the nearest to the Earth, also dispenses much influence; and things animate and inanimate sympathize and vary with her. By the changes of her illumination, rivers swell and are reduced; the tides of the sea are ruled by her risings and settings; and plants and animals are expanded or collapsed, if not entirely at least partially, as she waxes or wanes.
The stars likewise (as well the fixed stars as the planets), in performing their revolutions,[21] produce many impressions on the Ambient. They cause heats, winds, and storms, to the influence of which earthly things are conformably subjected.