PHYSICAL and LITERARY. 185 
in motion: why ought that motion to ceafe 
without a caufe? Action is neceflary to the 
production of motion, and no wonder if no- 
thing can deftroy the effect of one action but 
another action. The trite maxim, /uélata 
caufa, rollitur effeétus, isnot to be fo literally 
interpreted, as that an effect may not conti- 
nue, after its caufe ceafes to act. 
As we know fo little of the nature of that 
influence by which one being puts another 
in motion, or by which it excites motion in 
itfelf; with what reafon can we pofitively 
conclude its effects to be only momentary, 
when they every where appear to be fo per- 
manent? When motion is begun in any body, 
we attribute it to a certain action which we 
cannot poffibly explain; when a body conti- 
nues in the motion which it has once recei- 
ved, it appears to be a neceflary confequence 
of that action. We commonly indeed fay, 
that the body then moves on of itfelf; but the 
only queftion in debate is, Whether there be 
oecafion for a continual recruit of force, new 
_ impreffions, new follicitations to motion, 
like to what were at firft exerted by the mo- 
ving power ? 
ae UNLESS 
