Cicero and Seneca
Cicero in the last century before the present era, the statesman and philosopher of republican Rome, declared the stars to be gods. The divinity of the planets he explained by their occupying the sublime positions and by their following unerringly their paths.
This dogmatic thinking, changing the statute of faith but not the mode of thinking, existed in all ages: in the Rome of Cicero and Caesar, in the Rome of the Catholic Church, in modern observatories. The categorical manner in which the dissidents are castigated as being of unsound and vicious mind can be seen again in the burning of Giordano Bruno, in the compelling of Galileo to recant on his knees, in the coercing of the publisher of Worlds in Collision to give up the publication.
The notion expressed by Cicero that planets are divine bodies endowed with divine intelligence was deduced not fron the fact of their occupying the ethereal heights and moving unerringlythese attributes were only called upon to prove the existing idea of planets and stars being gods. And the source of this belief, deep-rooted and widespread, was in natural phenomena and extraordinary events of the past that grew dimmer with every passing generation.
Pliny, the Roman naturalist of the first century, knew to tell of interplanetary discharges: Heavenly fire is spit forth by the planet as crackling charcoal flies from a burning log. Interplanetary thunderbolts, according to him, have been caused in the past by each of the three upper planetsMars, Mercury and Saturn.
Seneca, the contemporary of Pliny, mentor of Nero and philosopher, was no mathematician and no astronomer; however, he rose to a clearer concept of comets as members of the planetary system. The prevailing view was that of Aristotle, according to whom the comets are exhalations of the earth in sublunar space, something of the nature of rainbows. Seneca regards them as bodies akin to planets, yet not planets, on very elongated orbits, and he knows that the Chaldeans have determined their orbits: Apollonius of Myndus asserts that comets are placed by the Chaldeans among the number of the wandering stars (i.e., planets) and that their orbits have been determined. (1) He knows that comets are seen only when they come close to the sun, or when they reach the lowest portion of their course. He opposes the view that the comets are unsubstantial bodies; the argument is brought forward that the sight can penetrate through comets and see the stars behind; Seneca answers that this is the case with the tails of the comets, not with their heads, through which one cannot see. He knows the view expounded by Artemidorus that the five planets are not the only stars with erratic courses, but merely the only ones of the class that have been observed. But innumerable others revolve in secret, unknown to us, either by the faintness of their light, or the situation of their orbit being such that they become visible only while they reach its extremities.
The day will yet come, wrote Seneca in his treatise De Cometis,
Seneca was compelled to take his own life when accused of plotting against Nero, his pupil. He was born in the same year as Jesus of Nazareth. In less than three hundred years Rome was to become the citadel of the new religion. Three forces kept science from progressing and brought about the dark ages: the invasion of the hordes coming from the east and north; the influence of the Church that imposed dogmas and made the human spirit unfree; and the scientific dogma that petrified itself in a thousand-year-long worship of Aristotlethrough all the years of the Middle Ages, with their crusades, scholasticism, and Black Death.
A strange amalgam of the Christian dogma and Aristotelianism becamem the credo of the Church, that regarded the world as finite, the earth as the center of the universe, and also immovable. The codification in the science of astronomy was performed by a distant pupil of Aristotle, Claudius Ptolemy, an Alexandrian astronomer and mathematician, the greatest authority in those sciences for his own agehe lived in the second centuryand for all successive centuries until the time of de Brahe and Kepler, almost fifteen hundred years later, it was the undisputed dogma.