A.D. 30, The crucifixion.
A.D. 529, Closing of Athenian schools. End of Greek philosophy.
A.D. 1125, (Approximate) Rise of the Universities of Bologna and Paris.
A.D. 1543, Publication of the “De Revolutionibus” of Copernicus. Beginning of Modern Science.
The intervals are 615, 499, 596, 418, years. In the history of metaphysics, we may take the following:
B.C. 322, Death of Aristotle.
A.D. 1274, Death of Aquinas.
A.D. 1804, Death of Kant.
The intervals are 1595 and 530 years. The former is about thrice the latter.
From these figures, no conclusion can fairly be drawn. At the same time, they suggest that perhaps there may be a rough natural era of about 500 years. Should there be any independent evidence of this, the intervals noticed may gain some significance.