The Authors
anſwer to the
fourth
ion.
anſwer to the
fourth
ion.
Of Natation,
Lib. 1. Prop. 7.
Lib. 1. Prop. 7.
Of Natation,
Lib. 1. Prop. 4.
Lib. 1. Prop. 4.
Plato denyeth
Poſitive
ty.
Poſitive
ty.
The Authors
defence of the
doctrine of Plato
and the Ancients,
who abſolutely
deny Levity:
defence of the
doctrine of Plato
and the Ancients,
who abſolutely
deny Levity:
According to
Plato there is no
Principle of the
Motion of
ſcent in Naturall
Bodies, ſave that
to the Centre.
Plato there is no
Principle of the
Motion of
ſcent in Naturall
Bodies, ſave that
to the Centre.
No cauſe of
the motion of
A cent, ſave the
Impulſe of the
Medium,
ing the
able in
tie.
the motion of
A cent, ſave the
Impulſe of the
Medium,
ing the
able in
tie.
Bodies aſcend
much ſwifter in
the Water, than
in the Air.
much ſwifter in
the Water, than
in the Air.
All Bodies
cending through
Water, loſe
their Motion,
comming to the
confines of the
Air.
cending through
Water, loſe
their Motion,
comming to the
confines of the
Air.
And, howbeit, Experience ſhewes, that the Bodies, ſucceſſively
leſs grave, do moſt expeditiouſly aſcend in water, it cannot be
ed, but that the Ignean Exhalations do aſcend more ſwiftly
through the water, than doth the Air: which Air is ſeen by
ence to aſcend more ſwiftly through the Water, than the Fiery
lations through the Air: Therefore, we muſt of neceſſity conclude,
that the ſaid Exhalations do much more expeditiouſly aſcend through
the Water, than through the Air; and that, conſequently, they are
moved by the Impulſe of the Ambient Medium, and not by an
ſick Principle that is in them, of avoiding the Centre of the Earth;
to which other grave Bodies tend.
leſs grave, do moſt expeditiouſly aſcend in water, it cannot be
ed, but that the Ignean Exhalations do aſcend more ſwiftly
through the water, than doth the Air: which Air is ſeen by
ence to aſcend more ſwiftly through the Water, than the Fiery
lations through the Air: Therefore, we muſt of neceſſity conclude,
that the ſaid Exhalations do much more expeditiouſly aſcend through
the Water, than through the Air; and that, conſequently, they are
moved by the Impulſe of the Ambient Medium, and not by an
ſick Principle that is in them, of avoiding the Centre of the Earth;
to which other grave Bodies tend.
The lighter
Bodies alſend
more ſwiftly
through Water.
Bodies alſend
more ſwiftly
through Water.
Fiery
ons ascend
row the Water
more ſwiftly
than doth the
Air; & the Air
aſcends more
ſwiftly thorow
the Water, than
Fire thorow the
Air.
ons ascend
row the Water
more ſwiftly
than doth the
Air; & the Air
aſcends more
ſwiftly thorow
the Water, than
Fire thorow the
Air.
To that which for a finall concluſion, Signor Buonamico produceth
of going about to reduce the deſcending or not deſcending, to the
eaſie and uneaſie Diviſion of the Medium, and to the predominancy
of the Elements: I anſwer, as to the firſt part, that that cannot in any
manner be admitted as a Cauſe, being that in none of the Fluid
Mediums, as the Air, the Water, and other Liquids, there is any
Reſiſtance againſt Diviſion, but all by every the leaſt Force, are
vided and penetrated, as I will anon demonſtrate: ſo, that of ſuch
Reſiſtance of Diviſion there can be no Act, ſince it ſelf is not in
ing. As to the other part, I ſay, that the predominancy of the
ments in Moveables, is to be conſidered, as far as to the exceſſe or
defect of Gravity, in relation to the Medium: for in that Action,
the Elements operate not, but only, ſo far as they are grave or light:
therefore, to ſay that the Wood of the Firre ſinks not, becauſe Air
predominateth in it, is no more than to ſay, becauſe it is leſs grave
than the Water. Yea, even the immediate Cauſe, is its being leſs
grave than the Water: and it being under the predominancy of the
Air, is the Cauſe of its leſs Gravity: Therefore, he that alledgeth the
predominancy of the Element for a Cauſe, brings the Cauſe of the
Cauſe, and not the neereſt and immediate Cauſe. Now, who knows
not that the true Cauſe is the immediate, and not the mediate?
Moreover, he that alledgeth Gravity, brings a Cauſe moſt perſpicuous
to Sence: The cauſe we may very eaſily aſſertain our ſelves;
whether Ebony, for example, and Firre, be more or leſs grave than
water: but whether Earth or Air predominates in them, who ſhall
make that manifeſt? Certainly, no Experiment can better do it
than to obſerve whether they ſwim or ſink. So, that he who knows,
not whether ſuch a Solid ſwims, unleſs when he knows that Air
dominates in it, knows not whether it ſwim, unleſs he ſees it ſwim,
for then he knows that it ſwims, when he knows that it is Air that
predominates, but knows not that Air hath the predominance, unleſs
he ſees it ſwim: therefore, he knows not if it ſwims, till ſuch time
as he hath ſeen it ſwim.
of going about to reduce the deſcending or not deſcending, to the
eaſie and uneaſie Diviſion of the Medium, and to the predominancy
of the Elements: I anſwer, as to the firſt part, that that cannot in any
manner be admitted as a Cauſe, being that in none of the Fluid
Mediums, as the Air, the Water, and other Liquids, there is any
Reſiſtance againſt Diviſion, but all by every the leaſt Force, are
vided and penetrated, as I will anon demonſtrate: ſo, that of ſuch
Reſiſtance of Diviſion there can be no Act, ſince it ſelf is not in
ing. As to the other part, I ſay, that the predominancy of the
ments in Moveables, is to be conſidered, as far as to the exceſſe or
defect of Gravity, in relation to the Medium: for in that Action,
the Elements operate not, but only, ſo far as they are grave or light:
therefore, to ſay that the Wood of the Firre ſinks not, becauſe Air
predominateth in it, is no more than to ſay, becauſe it is leſs grave
than the Water. Yea, even the immediate Cauſe, is its being leſs
grave than the Water: and it being under the predominancy of the
Air, is the Cauſe of its leſs Gravity: Therefore, he that alledgeth the
predominancy of the Element for a Cauſe, brings the Cauſe of the
Cauſe, and not the neereſt and immediate Cauſe. Now, who knows
not that the true Cauſe is the immediate, and not the mediate?
Moreover, he that alledgeth Gravity, brings a Cauſe moſt perſpicuous
to Sence: The cauſe we may very eaſily aſſertain our ſelves;
whether Ebony, for example, and Firre, be more or leſs grave than
water: but whether Earth or Air predominates in them, who ſhall
make that manifeſt? Certainly, no Experiment can better do it
than to obſerve whether they ſwim or ſink. So, that he who knows,
not whether ſuch a Solid ſwims, unleſs when he knows that Air
dominates in it, knows not whether it ſwim, unleſs he ſees it ſwim,
for then he knows that it ſwims, when he knows that it is Air that
predominates, but knows not that Air hath the predominance, unleſs
he ſees it ſwim: therefore, he knows not if it ſwims, till ſuch time
as he hath ſeen it ſwim.