nable us
to guess, for instance, that flame would burn, or ice would chill, if
touched. Nor even though on once touching flame we get our fingers
burnt, are mature philosophers like us to conclude, as if we had no more
intelligence than so many babies, that if we touch again we shall be
burnt again. All we have as yet learnt from the experiment is that the
sensation of touching fire has once been followed by the sensation of
burning, but nothing has occurred to suggest that in the first sensation
lurked any secret power of producing the second. And what a single
experiment does not prove, no number of repetitions of precisely the
same experiment with precisely the same results can prove. Even though
on a lengthened course of experience we have found that in every case of
our touching flame our fingers have been burnt, we are still as far as
ever from perceiving any bond of connection between the two events. We
do indeed believe that as flame when touched has hitherto invariably
burnt, so, whenever touched hereafter, it will hereafter invariably
burn; but this, according to Hume, we believe simply because by long
practice we have contracted such a habit of associating the idea of
touched flame with burnt fingers, that whenever we witness the one we
cannot help expecting the other.

Neither, if, withdrawing our eyes from the outward world, we cast them
inwardly upon the operations of our own minds, shall we, according to
Hume, any the more discover what we are in search of. What though we
know by experience that whatever, within certain limits, our will
appoints, our bodily organs or mental faculties will ordinarily perform;
that our limbs will move as we wish them, and our memory, reason, or
imagination bring forward ideas which we desire to contemplate, what
knowledge have we here beyond that of certain volitions and certain
other acts taking place in succession? What smallest evidence have we of
any connection between the volitions and the other acts? A volition is
an operation of the mind, is it not? and body is matter, is it not? And
do you pretend to know--can you form the smallest approach to a
guess--how mind is united with body, and how it is possible therefore
for the refined spiritual essence to actuate the gross material
substance. If you 'were empowered by a secret wish to remove mountains
or to control the planets in their orbit,' would such extensive
authority be one whit more inexplicable than the supposed