“Discover the force of the heavens O Men: Once recognized it can be put to use: No use could be seen in unknown things.”
Quote Number: 570
Source: Kepler, Johannes. “De fundamentis astrologiae certioribus [On the more Certain Fundamentals of Astrology or On Giving Astrology Sounder Foundations]” (written 1601; published 1602) in Opera Omnia, Vol. 1, Heyder & Zimmer, 1858, p. 417 (title-page). Online Here.
Source Notes: The translation was provided along with the original quote, and I do not know where it came from, nor can I confirm it is an accurate translation. If you have insight into this please leave a comment, thank you!