ion of a resemblance betwixt those
objects, of which we have had experience, and those, of which we have
had none; and therefore it is impossible this presumption can arise from
probability. The same principle cannot be both the cause and effect
of another; and this is, perhaps, the only proposition concerning that
relation, which is either intuitively or demonstratively certain.

Should any one think to elude this argument; and without determining
whether our reasoning on this subject be derived from demonstration or
probability, pretend that all conclusions from causes and effects are
built on solid reasoning: I can only desire, that this reasoning may be
produced, in order to be exposed to our examination. It may, perhaps,
be said, that after experience of the constant conjunction of certain
objects, we reason in the following manner. Such an object is always
found to produce another. It is impossible it coued have this effect,
if it was not endowed with a power of production. The power necessarily
implies the effect; and therefore there is a just foundation for drawing
a conclusion from the existence of one object to that of its usual
attendant. The past production implies a power: The power implies a new
production: And the new production is what we infer from the power and
the past production.

It were easy for me to shew the weakness of this reasoning, were I
willing to make use of those observations, I have already made, that
the idea of production is the same with that of causation, and that no
existence certainly and demonstratively implies a power in any other
object; or were it proper to anticipate what I shall have occasion to
remark afterwards concerning the idea we form of power and efficacy. But
as such a method of proceeding may seem either to weaken my system,
by resting one part of it on another, or to breed a confusion in my
reasoning, I shall endeavour to maintain my present assertion without
any such assistance.

It shall therefore be allowed for a moment, that the production of one
object by another in any one instance implies a power; and that this
power is connected with its effect. But it having been already proved,
that the power lies not in the sensible qualities of the cause; and
there being nothing but the sensible qualities present to us; I ask, why
in other instances you presume that the same power still exists, merely
upon the appearance of these qualities? Your appeal to past experien