C 5 1 6 ] ; 
mean by Force, and what by a double or a triple 
Force. This you muft do by a Definition which 
contains a Meafure of Force. Some primary Mea- 
fure of Force muft be taken tor granted, or laid 
down by way of Definition ; otherwife we can 
never reafon about its Quantity. And why then 
may you not take the Velocity for the primary Mea- 
fure as well as any other ? You will find none that 
is more fimple, more diftind, or more agreeable to 
the common Ufe of the Word Force: And he that 
rejects one Definition that has thefe Properties, has 
equal Right to rejed any other. I fay then, that it 
is impoffible, by mathematical Reafoningor Experi- 
ment, to prove, that the Force of a Body is as its 
Velocity, without taking for granted the thing you 
would prove, or fomething elfe that is no more 
evident than the thing to be proved. 
" «-J I Vi . • 1 1 - v / - • * - - - 
• : Sect. 7. 
Of the 'Lcibnitzian Meafure of Force. 
Let us next hear the Leibnitzian , who fays, that 
theForceof a Body is as the Square of its Velocity. If 
he lays this down as a Definition, I fhall rather 
agree to it, than quarrel about Words, and for the 
future fhall underftand him, by a quadruple Force 
to mean that which gives a double Velocity, by 9 
times the Force that which gives three times the 
Velocity, and fo on in duplicate Proportion. While 
he keeps by his Definition, it will not neceftarily 
lead him into any Error in Mathematics or Mecha- 
nics. For, however paradoxical his Conclufions 
may appear, however different in Words from theirs 
who 
