Rienk Vermij – Johannes Phocylides Holwarda and the Interpretation of New Stars in the Dutch Republic

21 September, 2017 - MA Coursework

Rienk Vermij, “Johannes Phocylides Holwarda and the Interpretation of New Stars in the Dutch Republic,” in Change and Continuity in Early Modern Cosmology, ed. Patrick J. Boner (New York: Springer, 2011).


The attention Kepler and Galileo paid to novae in the early-seventeenth century was the exception, not the norm, in an astronomical community which was at that time more inclined to ignore celestial irregularities or to notice and dismiss them on the assumption that irregularities tell us nothing of an essentially ordered cosmos. So when Kepler noticed a nova in the Whale 1604, and Fabricius the same in 1609, it generated no audible murmurings in the contemporaneous Dutch astronomical community. When Johannes Phocylides Holwarda “discovered” this Mira Ceti nearly 30 years later, naturally, he believed in the novelty of his observation. Sometime between and because of Mira Ceti’s two discoveries, novae had ceased to be curiosities of idle speculation and began to be considered legitimate subjects of philosophical speculation. Holwarda’s Mira Ceti treatise propelled this conversation and introduced variable stars (whose appearance presents with a periodicity and were included, even, in Descartes’s Principia Philosophiae).

The incorporation of novae into philosophical astronomical discourse, and especially through Holwarda and Mira Ceti, participated in an evolution in cosmological understanding and approach. Holwarda’s stance well represents this evolution. Holwara was motivated not by the eschatological significance of the nova, but instead by a desire to attack Aristotelianism (and to self-aggrandize). In so doing and unimpressed by philosophical argument and dogmatism, he shifted the standard of proof toward observation and discovery. Holwarda did away with the distinction between sub- and supralunar phenomena, but his polemics were less revolutionary than this might seem to indicate: he retained exhalations, simply considering celestial bodies (like comets and novae) to be the product of celestial, rather than terrestrial, exhalations. It would be easy, then, from our retrospective vantage, to minimize Holwarda’s proposals as half-hearted. His insistence on the epistemic authority of telescopic discoveries, parallax measurements, and the Copernican model at the expense of philosophical authorities should not be underestimated. Those insistences mirror and contribute to the empiric turn in the history of astronomy.









Leave a Reply

Your email address will not be published. Required fields are marked *