Tertius Interveniens, das ist Warnung an etliche Theologos, Medicos und Philosophos, sonderlich D. Philippum Feselium, dass sie bey billicher Verwerffung der Sternguckerischen Aberglauben, nicht das Kindt mit dem Badt außschütten, und hiermit ihrer Profession unwissendt zuwider handlen. .

Frankfurt am Main: Godtfriedt Tampach, 1610. 1st Edition. Hardcover. Very Good. 1st Edition. Hardcover. 4to (185 x 156 mm). 90 unnumbered leaves. Signatures: )(4, )()(4 A-V4 X2. Including title with small woodcut device, 2 woodcut initials, 4 preliminary leaves of dedication to Markgraf Georg Friedrich von Baden, 3 leaves of registrum, and final blank leaf X2. Bound in later plain vellum, blue-dyed edges. Paper browned, several stronger within text block area, a few brown spots, occasional annotations and text markings in contemporary red and black ink. Provenance: from a private Hungarian collection. A very good, clean and ample-margined copy. ----

EXCEEDINGLY RARE FIRST EDITION of Kepler's response to the discussion paper of Philip Feselius, Gründtlicher Discurs von der Astrologia Judiciaria (Strassburg, 1609), in which Feselius completely rejects astrology, especially attacking Helisaeus Röslin. This piece is a part of the huge polemic among scholars like Helisaeus Röslin, Philip Feselius and Kepler himself, in which Kepler defends Röslin, although he has previously criticized its exaggerations.
In his Tertius Interveniens Kepler set out his general views on astrology including some hypothesised mechanisms of interaction between planets and individual souls and "played the role of the 'third man in the middle' both against those who uncritically accepted grotesque astrological predictions and against those critics who would 'throw out the baby with the bath.' Writing in the vernacular German interspersed with numerous scraps of Latin, Kepler argued: 'No one should consider unbelievable that there should come out of astrological foolishness and godlessness also cleverness and holiness ... out of evil-smelling dung a golden corn scraped for by an industrious hen.' As part of the dung he counted most astrological rules, including the distinctions of the zodiacal signs and the meanings of the twelve houses. Kepler insisted, however, on the harmonic significance of the configurations of the planets among themselves and with ecliptic points such as the ascendant. The stars do not compel, he said, but they impress upon the soul a special character." (DSB).
According to the German national bibliography, there is another variant known (VD17 547: 738138C) with "Thambach" in the imprint on the title-page. The book is rare outside Germany. Whereas OCLC/Worldcat locates 15 libraries in Germany and 4 in the UK, only one copy is traced in Canada and no copy in the US. References: Caspar 33; DSB VII, p.299; VD 17 39:120046N. - Visit our website to see more images!