On November 15, three hundred years will have passed since Johannes Kepler, one of the founders of modern astronomy and of modem science as a whole, closed his eyes for the last time. Measured against the brevity of our own individual lives, three hundred years is a long time, but measured with an eye to the laborious progress of science as a social phenomenon of civilization, it is but a short span of time, encompassing such a closely related set of intellectual approaches that, from this stand-point, Johannes Kepler is regarded as a member of the present epoch of civilization — indeed, as one of those leading minds whose thoughts continue to be applied in new ways by scientists.