
Epistemology of the
sciences
701
geometry. Hence we construct so many lines, we fashion so many circles, we
imagine so many points, we devise so many eccentric and
epicyclic
orbs, and even
little
epicycles
as
well.
63
Frischlin is not content merely to deny the physical reality of astronomers'
planetary models. Such hypotheses are, he maintains, actively misleading if
used for purposes other
than
the calendrical and chronometric uses licensed
by
the Scriptures, for they encourage astrologers and they foster the
erroneous
view
that
the celestial motions really are irregular.
64
In his
Prooemium mathematicum
of 1567 Petrus Ramus
gives
a mocking
history of astronomy in which he denounces it for its unnecessary use of
fictitious hypotheses; and he pleads for the restoration of the pristine
'astronomy without hypotheses' possessed by the Babylonians, Egyptians
and Greeks before Eudoxus.
65
It seems
that
this is a plea for a calculus of
apparent
celestial coordinates, a plea apparently premised on a radical
scepticism about our capacity to acquire knowledge
of
the
true
dispositions
and motions of heavenly bodies.
66
Neither Frischlin nor Ramus offers sustained arguments for the
unattainability of knowledge of the heavens. In Nicolaus Ursus' (Baer)
scurrilous treatise of 1597, written to
rebut
the charge of plagiarism of
Tycho
Brahe's world-system, we find a more systematically defended
sceptical
position.
67
Firstly, Ursus cites the crass absurdity of all past
hypotheses in support
of
his assertion
that
it is scarcely possible in astronomy
to arrive at
true
hypotheses.
68
The history of hypotheses which
follows,
a
history partly derived from Ramus, in which he mocks all the various
world-systems
that
have been proposed, is evidently supposed to substanti-
ate the premise
of
this induction on the history
of
science.
69
Secondly,
there
is
what may, with a degree of anachronism, be called an argument from
observational equivalence. Ursus draws
attention
to the existence of very
different hypotheses: those of Ptolemy, those of Copernicus, those of
Tycho
and those of his own variant of the Tychonic system, all equally
63.
Frischlin 1586, p. 41: 'Cum enim Deus
Opifex
rerum,
ilia
corpora tam procul a sensibus nostris
removerit: ut (quod in aliarum rerum scientiis faceré possumus) principia demonstrationum non
queamus ex ipsis gignere, et oikeia ac vernácula invenire: quibus postea singularum apparentiarum
causas reddamus: ideo nos ad aliena confugimus praesidia, petimusque nobis hypotheses, ex
arithmetica et geometria. Nam hinc tot
lineas extruimus, tot circuios fingimus, tot puncta
imaginamur, tot orbes eccentricos et
epicyclos,
imo etiam
epicycliscos
comminiscimur.'
64.
Ibid., pp. 258-60. 65. Ramus 1567, pp.
211-17.
66.
Ramus' plea for an astronomy without hypotheses has been variously interpreted: see, for
example,
Hooykaas 1958, ch. 9;
Aiton
1975;
Dictionary
of
Scientific
Biography 1970-80, xi, pp. 286-
90 ('Peter Ramus'). 67. Ursus 1597; partial translation in N.
Jardine
1984.
68. Ursus 1597,
sigs.
A iv
r
, B iv
v
. 69. Ibid.,
sigs.
c
ii
R
-D
ii
v
.
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