Galilei, Galileo - The systems of the world

Galilei, Galileo, The systems of the world, 1661

None
Concordance
Figures
Thumbnails

List of thumbnails

< >

11	12
13	14
15	16
17	18
19	20

< >

and others more ſlowly than the ſimple; as for example, Lead, and
Wood, in compariſon of earth; and therefore amongſt theſe mo
tions, which call you the ſimple, and which the mixt?

SIMPL. I would call that ſimple motion, which is made by a
ſimple body, and mixt, that of a compound body.

SAGR. Very well, and yet Simplicius a little before you ſaid,
that the ſimple, and compound motions, diſcovered which were
mixt, and which were ſimple bodies; now you will have me by
ſimple and mixt bodies, come to know which is the ſimple, and
which is the compound motion: an excellent way to keep us igno
rant, both of motions and bodies. Moreover you have alſo a little
above declared, how that a greater velocity did not ſuffice, but
you ſeek a third condition for the definement of ſimple motion, for
which Ariſtotle contented himſelf with one alone, namely, of the
ſimplicity of the Space, or Medium: But now according to you,
the ſimple motion, ſhall be that which is made upon a ſimple line,
with a certain determinate velocity, by a body ſimply moveable.
Now be it as you pleaſe, and let us return to Ariſtotle, who defi
neth the mixt motion to be that compounded of the right, and cir
cular, but produceth not any body, which naturally moveth with
ſuch a motion.

SALV. I come again to Ariſtotle, who having very well, and
Methodically begun his diſcourſe, but having a greater aim to
reſt at, and hit a marke, predefigned in his minde, then that to
which his method lead him, digreſſing from the purpoſe, he comes
to aſſert, as a thing known and manifeſt, that as to the motions
directly upwards or downwards, they naturally agree to Fire, and
Earth; and that therefore it is neceſſary, that beſides theſe bodies,
which are neer unto us, there muſt be in nature another, to which
the circular motion may agree: which ſhall be ſo much the more
excellent by how much the circular motion is more perfect, then the
ſtreight, but how much more perfect that is than this, he deter
mines from the greatneſs of the circular lines perfection above the

right line; calling that perfect, and this imperfect; imperfect, be
cauſe if infinite it wanteth a termination, and end: and if it be fi
nite, there is yet ſomething beyond which it may be prolonged.
This is the baſis, ground work, and maſter-ſtone of all the Fabrick
of the Aristotelian World, upon which they ſuperſtruct all their
other properties, of neither heavy nor light, of ingenerable incor
ruptible, exemption from all motions, ſome onely the local, &c.
And all theſe paſſions he affirmeth to be proper to a ſimple body
that is moved circularly; and the contrary qualities of gravity,
levity, corruptibility, &c. he aſſigns to bodies naturally moveable
in a ſtreight line, for that if we have already diſcovered defects in
the foundation, we may rationally queſtion what ſoever may far

Text layer

Text normalization

Search