|Galilei, Galileo Dialogues on two world systems 1661, tr. Salusbury, Thomas|
buckler of the little Treatise of Conclusions, or Disquisitions Ma
thematical, the oppugnations of which it would be good to be
gin to produce.
SIMP. I will, if you so please, reserve them to the last, as those
that are of latest invention.
SALV. It will therefore be necessary, that in conformity to the
method hitherto observed, you do orderly, one by one, propound
the arguments, on the contrary, aswell of Aristotle, as of the o
ther ancients, which shall be my task also, that so nothing may e
scape our strict consideration and examination; and likewise Sa
gredus, with the vivacity of his wit, shall interpose his thoughts, as
he shall finde himself inclined.
SAGR. I will do it with my wonted freedome; and your com
mands shall oblige you to excuse me in so doing.
SALV. The favour will challenge thanks, and not an excuse.
But now let Simplicius begin to propose those doubts which dis
swade him from believing that the Earth, in like manner, as the
other pianets, may move round about a fixed centre.
SIMP. The first and greatest difficulty is the repugnance and
incompatibility that is between being in the centre, and being far
from it; for if the Terrestrial Globe were to move in a year by
the circumference of a circle, that is, under the Zodiack, it is im
possible that it should, at the same time, be in the centre of the Zo
diack; but that the Earth is in the said centre Aristotle, Ptolomy,
and others have many wayes proved.
SALV. You very well argue, aud there is no question but that
one that would make the Earth to move in the circumference of a
circle, must first of necessity prove, that it is not in the centre of
that same circle; it now followeth, that we enquire, whether the
Earth be, or be not in that centre, about which, I say, that it tur
neth, and you say that it is fixed; and before we speak of this, it
is likewise necessary that we declare our selves, whether you and I
have both the same conceit of this centre, or no. Therefore tell
me, what and where is this your intended centre?
SIMP. When I speak of the centre, I mean that of the Uni
verse, that of the World, that of the Starry Sphere.
SALV. Although I might very rationally put it in dispute, whe
ther there be any such centre in nature, or no; being that neither
you nor any one else hath ever proved, whether the World be fi
nite and figurate, or else infinite and interminate; yet nevertheless
granting you, for the present, that it is finite, and of a terminate
Spherical Figure, and that thereupon it hath its centre; it will be
requisite to see how credible it is that the Earth, and not rather
some other body, doth possesse the said centre.
It hath not been
hitherto proved by
any, whether the
World be finite or
SIMP. That the world is finite, terminato, and spherical, Ari-