Disputation on Planetary Systems from Chapter 4 of
In Sphaeram Ioannis de Sacro Bosco Commentarius.
Venice, 1596. Edited by James M. Lattis.
(Emended by the editor with corrections from later editions)
Some Clavius background
(Links to some related Web sites are at bottom of this page.)
Biographical sketch of Clavius
Very selective bibliography on Clavius
The primary text
Brief notes on the text
This is Clavius's
on the cosmological systems that
competed with each other in the late
Commentary on the Sphere of Sacrobosco
was published many times in many places across Europe
for over forty years
and employed as an introductory text book
at many schools.
Thus, it must have been known to a significant
fraction of persons educated from about 1570
to around 1615.
Occupying most of Chapter 4,
is a remarkable and important
summary of the diversity of cosmological
thought in the late sixteenth century.
Few texts are better qualified to bear witness to the context
in which the literate public would have received
the cosmological debates of that era.
The text was transcribed directly
from the original printed version of 1596.
Obvious typographical errors
have been corrected,
and a few corrections have been taken
from the final edition of 1611.
Page breaks are indicated by a page
reference enclosed in pointy brackets.
Italics are used as in the original,
i.e. generally to indicate quotations.
E.g. the text begins with a quotation
on which Clavius,
like many other medieval and early modern
wrote his commentary.
Italics also indicate titles.
The original contains marginal notes,
which here appear enclosed by hyphens.
Images, scanned from the 1596 edition,
appear in roughly the same place
with respect to the text
as in the printed book.
The Latin text
Opening and apologia
Plan of the argument
What eccentrics and epicycles are
Nature of planetary motion
Plurality of planetary motions and orbs
Observations supporting eccentrics I: Variations
in apparent magnitude
Criticisms of the preceding
Observations supporting eccentrics II: Variations
in proper motion
Observations supporting eccentrics III:
Variability of eclipses
Observations supporting eccentrics IIII: Diurnal
Observations supporting epicycles I: Variations
in apparent magnitude at apogee
Observations supporting epicycles II: Variations
in proper motion at apogee
Observations supporting epicycles III:
Variability of lunar eclipses
Observations supporting epicycles IIII:
Variability of lunar parallax
Other arguments 1: Dynamics of celestial
Other arguments 2: Rejection of the alternatives,
fluid heavens and concentric spheres
Other arguments 3: Proper methodology in natural
Response of the adversaries
Confutation of the response of the adversaries:
How this pertains to Copernicus
Arguments against eccentrics and epicycles
Solutions of the arguments
Solution of Fracastoro's arguments
Loyola University's Jesuits and the Science
MacTutor History of Mathematics archive
Clark University's History of Mathematics Page
Home page of Jim Lattis
James M. Lattis