maxim both in natural and moral philosophy, that
an object, which exists for any time in its full perfection without
producing another, is not its sole cause; but is assisted by some other
principle, which pushes it from its state of inactivity, and makes it
exert that energy, of which it was secretly possest. Now if any cause
may be perfectly co-temporary with its effect, it is certain, according
to this maxim, that they must all of them be so; since any one of them,
which retards its operation for a single moment, exerts not itself
at that very individual time, in which it might have operated; and
therefore is no proper cause. The consequence of this would be no less
than the destruction of that succession of causes, which we observe in
the world; and indeed, the utter annihilation of time. For if one cause
were co-temporary with its effect, and this effect with its effect, and
so on, it is plain there would be no such thing as succession, and all
objects must be co-existent.

If this argument appear satisfactory, it is well. If not, I beg the
reader to allow me the same liberty, which I have used in the preceding
case, of supposing it such. For he shall find, that the affair is of no
great importance.

Having thus discovered or supposed the two relations of contiguity and
succession to be essential to causes and effects, I find I am stopt
short, and can proceed no farther in considering any single instance
of cause and effect. Motion in one body is regarded upon impulse as the
cause of motion in another. When we consider these objects with utmost
attention, we find only that the one body approaches the other; and that
the motion of it precedes that of the other, but without any, sensible
interval. It is in vain to rack ourselves with farther thought and
reflection upon this subject. We can go no farther in considering this
particular instance.

Should any one leave this instance, and pretend to define a cause, by
saying it is something productive of another, it is evident he would say
nothing. For what does he mean by production? Can he give any definition
of it, that will not be the same with that of causation? If he can; I
desire it may be produced. If he cannot; he here runs in a circle, and
gives a synonimous term instead of a definition.

Shall we then rest contented with these two relations of contiguity and
succession, as affording a complete idea of causation? By, no means. An
object may be contiguous an