1
Now this acceleration of motion is never made, but when the
moveable in moving acquireth it; nor is its acquiſt other than an
approaching to the place deſired, to wit, whither its natural
clination attracts it, and thither it tendeth by the ſhorteſt way;
namely, by a right line. We may upon good grounds therefore
ſay, That Nature, to confer upon a moveable firſt conſtituted in
reſt a determinate velocity, uſeth to make it move according to
a certain time and ſpace with a right motion. This preſuppoſed,
let us imagine God to have created the Orb v. g. of Jupiter, on
which he had determined to confer ſuch a certain velocity, which
it ought afterwards to retain perpetually uniform; we may with
Plato ſay, that he gave it at the beginning a right and accelerate
motion, and that it afterwards being arrived to that intended
gree of velocity, he converted its right, into a circular motion,
the velocity of which came afterwards naturally to be uniform.
Now this acceleration of motion is never made, but when the
moveable in moving acquireth it; nor is its acquiſt other than an
approaching to the place deſired, to wit, whither its natural
clination attracts it, and thither it tendeth by the ſhorteſt way;
namely, by a right line. We may upon good grounds therefore
ſay, That Nature, to confer upon a moveable firſt conſtituted in
reſt a determinate velocity, uſeth to make it move according to
a certain time and ſpace with a right motion. This preſuppoſed,
let us imagine God to have created the Orb v. g. of Jupiter, on
which he had determined to confer ſuch a certain velocity, which
it ought afterwards to retain perpetually uniform; we may with
Plato ſay, that he gave it at the beginning a right and accelerate
motion, and that it afterwards being arrived to that intended
gree of velocity, he converted its right, into a circular motion,
the velocity of which came afterwards naturally to be uniform.
A moveable
ing in a ſtate of
reſt, ſhall not move
unleſs it have an
inclination to ſome
particular place.
ing in a ſtate of
reſt, ſhall not move
unleſs it have an
inclination to ſome
particular place.
SAGR. I hearken to this Diſcourſe with great delight; and I
believe the content I take therein will be greater, when you have
ſatisfied me in a doubt: that is, (which I do not very well
prehend) how it of neceſſity enſues, that a moveable departing
from its reſt, and entring into a motion to which it had a natural
inclination, it paſſeth thorow all the precedent degrees oſ tardity,
comprehended between any aſſigned degree of velocity, and the
ſtate of reſt, which degrees are infinite? ſo that Nature was not
able to confer them upon the body of Jupiter, his circular
on being inſtantly created with ſuch and ſuch
believe the content I take therein will be greater, when you have
ſatisfied me in a doubt: that is, (which I do not very well
prehend) how it of neceſſity enſues, that a moveable departing
from its reſt, and entring into a motion to which it had a natural
inclination, it paſſeth thorow all the precedent degrees oſ tardity,
comprehended between any aſſigned degree of velocity, and the
ſtate of reſt, which degrees are infinite? ſo that Nature was not
able to confer them upon the body of Jupiter, his circular
on being inſtantly created with ſuch and ſuch
SALV. I neither did, nor dare ſay, that it was impoſſible for
God or Nature to confer that velocity which you ſpeak of,
diately; but this I ſay, that de facto ſhe did not doit; ſo that the
doing it would be a work extra-natural, and by confequence
raculous.
God or Nature to confer that velocity which you ſpeak of,
diately; but this I ſay, that de facto ſhe did not doit; ſo that the
doing it would be a work extra-natural, and by confequence
raculous.
SAGR. Then you believe, that a ſtone leaving its reſt, and
tring into its natural motion towards the centre of the Earth,
ſeth thorow all the degrees of tardity inferiour to any degree of
velocity?
tring into its natural motion towards the centre of the Earth,
ſeth thorow all the degrees of tardity inferiour to any degree of
velocity?
SALV. I do believe it, nay am certain of it; and ſo certain,
that I am able to make you alſo very well ſatisfied with the truth
thereof.
that I am able to make you alſo very well ſatisfied with the truth
thereof.
SAGR. Though by all this daies diſcourſe I ſhould gain no
more but ſuch a knowledge, I ſhould think my time very well
beſtowed.
more but ſuch a knowledge, I ſhould think my time very well
beſtowed.
SALV. By what I collect from our diſcourſe, a great part of
your ſcruple lieth in that it ſhould in a time, and that very ſhort,
paſs thorow thoſe infinite degrees of tardity precedent to any
locity, acquired by the moveable in that time: and therefore
fore we go any farther, I will ſeek to remove this difficulty, which
your ſcruple lieth in that it ſhould in a time, and that very ſhort,
paſs thorow thoſe infinite degrees of tardity precedent to any
locity, acquired by the moveable in that time: and therefore
fore we go any farther, I will ſeek to remove this difficulty, which