on which I would insist。 The bread； which I formerly eat；
nourished me； that is； a body of such sensible qualities
was； at that time； endued with such secret powers： But does
it follow； that other bread must also nourish me at another
time； and that like sensible qualities must always be
attended with like secret powers？ The consequence seems
nowise necessary。 At least； it must be acknowledged that
there is here a consequence drawn by the mind； that there is
a certain step taken； a process of thought； and an
inference； which wants to be explained。 These two
propositions are far from being the same； ； and 。
I shall allow； if you please； that the one proposition may
justly be inferred from the other： I know； in fact； that it
always is inferred。 But if you insist that the inference is
made by a chain of reasoning； I desire you to produce that
reasoning。 The connexion between these propositions is not
intuitive。 There is required a medium； which may enable the
mind to draw such an inference； if indeed it be drawn by
reasoning and argument。 What that medium is； I must confess；
passes my comprehension； and it is incumbent on those to
produce it； who assert that it really exists； and is the
origin of all our conclusions concerning matter of fact。
This negative argument must certainly； in process of
time； become altogether convincing； if many penetrating and
able philosophers shall turn their enquiries this way and no
one be ever able to discover any connecting proposition or
intermediate step； which supports the understanding in this
conclusion。 But as the question is yet new； every reader may
not trust so far to his own penetration； as to conclude；
because an argument escapes his enquiry； that therefore it
does not really exist。 For this reason it may be requisite
to venture upon a more difficult task； and enumerating all
the branches of human knowledge； endeavour to show that none
of them can afford such an argument。
All reasonings may be divided into two kinds； namely；
demonstrative reasoning； or that concerning relations of
ideas； and moral reasoning； or that concerning matter of
fact and existence。 That there are no demonstrative
arguments in the case seems evident； since it implies no
contradiction that the course of nature may change； and that
an object； seemingly like those which we have experienced；
may be attended with different or contrary effects。 May I
not clearly and distinctly conceive that a body； falling
from the clouds； and which； in all other respects； resembles
snow； has yet the taste of salt or feeling of fire？ Is there
any more intelligible proposition than to affirm； that all
the trees will flourish in D/ECEMBER and J/ANUARY； and
decay in M/AY and J/UNE？ Now whatever is intelligible； and
can be distinctly conceived； implies no contradiction； and
can never be proved false by any demonstrative argument or
abstract reasoning 。
If we be； therefore； engaged by arguments to put trust
in past experience； and make it the standard of our future
judgment； these arguments must be probable only； or such as
regard matter of fact and real existence according to the
division above mentioned。 But that there is no argument of
this kind； must appear； if our explication of that species
of reasoning be admitted as solid and satisfactory。 We have
said that all arguments concerning existence are founded on
the relation of cause and effect； that our knowledge of that
relation is derived entirely from experience； and that all
our experimental conclusions proceed upon the supposition
that the future will be conformable to the past。 To
endeavour； therefore； the proof of this last supposition by
probable arguments； or arguments regarding existence； must
be evidently going in a circle； and taking that for granted；
which is the very point in question。
In reality； all arguments from experience are founded
on the similarity which we discover among natural objects；
and by which we are induced to expect effects similar to
those which we have found to follow from such objects。 And
though none but a fool or madman will ever pretend to
dispute the authority of experience； or to reject that great
guide of human life； it may surely be allowed a philosopher
to have so much curiosity at least as to examine the
principle of human nature； which gives this mighty authority
to experience； and makes us draw advantage from that
similarity which nature has placed among different objects。
From causes which； appear ； we expect similar
effects。 This is the sum of all our experimental
conclusions。 Now it seems evident that； if this conclusion
were formed by reason； it would be as perfect at first； and
upon one instance； as after ever so long a course of
experience。 But the case is far otherwise。 Nothing so like
as eggs； yet no one； on account of this appearing
similarity； expects the same taste and relish in all of
them。 It is only after a long course of uniform experiments
in any kind； that we attain a firm reliance and security
with regard to a particular event。 Now where is that process
of reasoning which； from one instance； draws a conclusion；
so different from that which it infers from a hundred
instances that are nowise different from that single one？
This question I propose as much for the sake of information；
as with an intention of raising difficulties。 I cannot find；
I cannot imagine any such reasoning。 But I keep my mind
still open to instruction； if any one will vouchsafe to
bestow it on me。
Should it be said that； from a number of uniform
experiments； we a connexion between the sensible
qualities and the secret powers； this； I must confess； seems
the same difficulty； couched in different terms。 The
question still recurs； on what process of argument this
is founded？ Where is the medium； the interposing
ideas； which join propositions so very wide of each other？
It is confessed that the colour； consistence； and other
sensible qualities of bread appear not； of themselves； to
have any connexion with the secret powers of nourishment and
support。 For otherwise we could infer these secret powers
from the first appearance of these sensible qualities；
without the aid of experience； contrary to the sentiment of
all philosophers； and contrary to plain matter of fact。
Here； then； is our natural state of ignorance with regard to
the powers and influence of all objects。 How is this
remedied by experience？ It only shows us a number of uniform
effects； resulting from certain objects； and teaches us that
those particular objects； at that particular time； were
endowed with such powers and forces。 When a new object；
endowed with similar sensible qualities； is produced； we
expect similar powers and forces； and look for a like
effect。 From a body of like colour and consistence with
bread we expect like nourishment and support。 But this
surely is a step or progress of the mind； which wants to be
explained。 When a man says； And when he says； ； he is not guilty of a tautology； nor are these
propositions in any respect the same。 You say that the one
proposition is an inference from the other。 But you must
confess that the inference is not intuitive； neither is it
demonstrative： Of what nature is it； then？ To say it is
experimental； is begging the question。 For all inferences
from experience suppose； as their foundation； that the
future will resemble the past； and that similar powers will
be conjoined with similar sensible qualities。 If there be
any suspicion that the course of nature may change； and that
the past may be no rule for the future； all experience
becomes useless； and can give rise to no inference or
conclusion。 It is impossible； therefore； that any arguments
from experience can prove this resemblance of the past to
the future； since all these arguments are founded on the
supposition of that resemblance。 Let the course of things be
allowed hitherto ever so regular； that alone； without some
new argument or inference； proves not that； for the future；
it will continue so。 In vain do you pretend to have learned
the nature of bodies from your past experience。 Their secret
nature； and consequently all their effects and influence；
may change； without any change in their sensible qualities。
This happens sometimes； and with regard to some objects： Why
may it not happen always； and with regard to all objects？
What logic； what process or argument secures you against
this supposition？ My practice； you say； refutes my doubts。
But you mistake the purport of my question。 As an agent； I
am quite satisfied in the point； but as a philosopher； who
has some share of curiosity； I will not say scepticism； I
want to learn the foundation of this inference。 No reading；
no enquiry has yet been able to remove my difficulty； or
give me satisfaction in a matter of such importance。 Can I
do better than propose the difficulty to the public； even
though； perhaps； I have small hopes of obtaining a solution？
We shall at least； by this means； be sensible of our
ignorance； if we do not augment our knowledge。
I must confess that a man is guilty of unpardonable
arrogance who concludes； because an argument has escaped his
own investigation； that therefore it does not really exist。
I must also confess that； though all the learned； for
several ages； should have employed themselves in fruitless
search upon any subject； it may still； perhaps； be rash to
conclude positively that the subject must； therefore； pass
all human comprehension。 Even though we examine all the
sources of our knowledge； and conclude them unfit for such a
subject； there may still remain a suspicion； that the
enumeration is not complete； or the examination not
accurate。 But with regard to the present subject； there are
some considerations