The inevitable logical outcome of astrological faith is the doctrine of Necessity. The invariability of the celestial motions suggested to early astrologers that there must be a higher power transcending and controlling them, and this power could be none other than Necessity. But, since the stars by their movements and positions were the regulators of mundane events and human affairs, it followed that human destiny on the earth was also under the sway of this relentless power of Necessity or Fate. Now it was the Stoics alone who developed a thorough-going fatalism and at the same time made it consistent with practical life and virtue. They taught that man could best find himself in complete submission to the divine law of destiny. The early Babylonian astrologers who originated the doctrine of necessity did not develop it to its logical consequences. Reasoning from certain very unusual occurrences that sometimes took place in the heavens, such as the appearance of comets, meteors and falling stars, they reached the conclusion that divine will at times arbitrarily interfered in the destined course of nature. So priests foretold future events from the configuration of the heavens, but professed ability to ward off threatened evils by spells and incantations, or, by purifications and sacrifices, to make the promised blessings more secure. Now the fatalism of Chaucer's characters is something like this. The general belief in the determination of human destiny by Fortune or Necessity is present and is expressed usually at moments of deep despair, when the longings of the heart and the struggles of the will have been relentlessly thwarted. When the Trojans decree that Criseyde must go to the Greeks in exchange for Antenor, Troilus pleads with Fortune: "Than seyde he thus, 'Fortune! allas the whyle! What have I doon, what have I thus a-gilt? How mightestow for reuthe me bigyle? Is ther no grace, and shall I thus be spilt? Shal thus Criseyde awey, for that thou wilt? Allas! how maystow in thyn herte finde To been to me thus cruel and unkinde? . . . . . . . . . . . . . . . . . . . . . . . . Allas! Fortune! if that my lyf in Ioye Displesed hadde un-to thy foule envye, Why ne haddestow my fader, king of Troye, By-raft the lyf, or doon my bretheren dye, Or slayn my-self, that thus compleyne and crye, I, combre-world, that may of no-thing serve, But ever dye, and never fulle sterve?'"[168]