44 ESSAYS.ann OBSERVATIONS 
was hisown child. New difcoveries are al- 
ways received with fome degree of hefitati- 
on: becaufe it is the effect of novelty to 
preduce doubts as well as furprize. But 
now, that this theory is fully eftablifhed by 
habit, as well,as by reafoning, and has got a 
firm hold of the mind; itis not obvious, why 
later philofophers fhould affect the fame re- 
ferve. For my part, ] cannot fee any diffi- 
culty of explaining the caufe of attraction or 
gravity, more than of explaining the caufe 
of a body’s continuing in the fame degree 
of motion with which it begins to move. And 
this I fhall now attempt. 
Ir is above eftablifhed, that the continua- 
tion of motion in bodies muft be an effet of 
a power inherent in all matter, of preferving 
that degree of celerity which is once beftow- 
ed upon it. The body, by this power, is di- 
rected to move in a ftreight line. But we 
perceive nothing in the nature of this power 
to confine its operation toa ftreight line, more, 
than a curve. And we may fuppofe the 
power ftill further varied, to make the body, 
inftead of moving in a ftreight line, or in a 
curve, to direct its equable motion towards © 
any other given body, within a certain di- 
ftance 
