18 ESSAYS ann OBSERVATIONS 
be a property inherent in matter; from this 
confideration, that, if body had an actual ten- 
dency to fall down, it could not at the fame 
time refift the downward motion by its inertia. 
Which reafoning plainly fuppofes, that there 
is a real active refiftance arifing from inertia. 
And indeed, tho’ he exprefsly intends to de- 
ny the {malleft activity in matter, yet he eve- 
ry where {peaks of inertia, as a conatus or ten- 
dency effential to matter, by which it makes 
a violent oppofition to the power of gravity, 
and other active powers. This being a que- 
{tion of the utmoft importance, it may not 
be amifs to offer an amendment upon that ar- 
gument, which will free it from any incon- 
fiftency, and place it on itstrue bottom, on 
which aloneit can ftand its ground. . To prove 
then that gravity does not proceed from any 
internal active force of any kind, either in the 
earth or fuch bodies as fall towards it; it is on- 
ly neceflary to affume one axiom, that no fub- 
{tance can atively tend to move to two oppo- 
fite fides, at the fame time. It is eafy to 
conceive that a body may be pufhed or drawn 
to oppofite fides, by twocontrary external for- 
ces: in which cafe, if they are equal, the body 
will remain at reft; if unequal, it will be mo- 
ved 
