David Hume - A Treatise on the Human Nature [1 eBook - PDF] (Philosophy)

A Treatise of Human Nature: Being an attempt to introduce the experimental Method of Reasoning into Moral subjects.

Rara temporum felicitas, ubi sentire, quae belis; & quae sentias, decere licet.
                                                TACIT

Introduction:
Nothing is more usual and more natural for those, who pretend to discover anything new to the
world in philosophy and the sciences, than to insinuate the praises of their own systems, by
decrying all those, which have been advanced before them. And indeed were they content with
lamenting that ignorance, which we still lie under in the most important questions, that can come
before the tribunal of human reason, there are few, who have an acquaintance with the sciences, that would not readily agree with them. 'Tis easy for one of judgment and learning, to perceive the weak foundation even of those systems, which have obtained the greatest credit, and have carried their pretensions highest to accurate and profound reasoning. Principles taken upon trust, consequences lamely deduced from them, want of coherence in the parts, and of evidence in the whole, these are every where to be met with in the systems of the most eminent philosophers, and seem to have drawn disgrace upon philosophy itself.

Nor is there requir'd such profound knowledge to discover the present imperfect condition of the
sciences, but even the rabble without doors may, judge from the noise and clamour, which t hey
hear, that all goes not well within. There is nothing which is not the subject of debate, and in which
men of learning are not of contrary opinions. The most trivial question escapes not our controversy,
and in the most momentous we are not able to giv e any certain decision. Disputes are multiplied, as
if every thing was uncertain; and these disputes are managed with the greatest warmth, as if every
thing was certain. Amidst all this bustle 'tis not. reason, which carries the prize, but eloquence; and
no man needs ever despair of gaining proselytes to the most extravagant hypothesis, who has art
enough to represent it in any favourable colours. The victory is not gained by the men at arms, who
manage the pike and the sword; but by the trumpeters, drummers, and musicians of the army.

From hence in my opinion arises that common prejudice against metaphysical reasonings of all
kinds, even amongst those, who profess themselves scholars, and have a just value for every other
part of literature. By metaphysical reasonings, they do not understand those on any particular
branch of science, but every kind of argument, which is any way abstruse, and requires some
attention to be comprehended. We have so often lost our labour in such researches, that we
commonly rej ect them without hesitation, and resolve, if we must for ever be a prey to errors and
delusions, that they shall at least be natural and entertaining. And indeed nothing but the most
determined scepticism, along with a great degree of indolence, can justif y this aversion to
metaphysics. For if truth be at all within the reach of human capacity, 'tis certain it must lie very
deep and abstruse: and to hope we shall arrive at it without pains, while the greatest geniuses have
failed with the utmost pains, mustcertainly be esteemed sufficiently vain and presumptuous. I
pretend to no such advantage in the philosophy I am going to unfold, and would esteem it a strong
presumption against it, were it so very easy and obvious.

'Tis evident, that all the sciences ha ve a relation, greater or less, to human nature: and that however wide any of them may seem to run from it, they still return back by one passage or another. Even. Mathematics, Natural Philosophy, and Natural Religion, are in some measure dependent on the
science of MAN; since the lie under the cognizance of men, and are judged of by their powers and
faculties. 'Tis impossible to tell what changes and improvements we might make in these sciences
were we thoroughly acquainted with the extent and force of human understanding, and cou'd
explain the nature of the ideas we employ, and of the operations we perform in our reasonings. And
these improvements are the more to be hoped for in natural religion, as it is not content with
instructing us in the nature of su perior powers, but carries its views farther, to their disposition
towards us, and our duties towards them; and consequently we ourselves are not only the beings,
that reason, but also one of the objects, concerning which we reason.

If therefore the scien ces of Mathematics, Natural Philosophy, and Natural Religion, have such a
dependence on the knowledge of man, what may be expected in the other sciences, whose
connexion with human nature is more close and intimate? The sole end of logic is to explain the
principles and operations of our reasoning faculty, and the nature of our ideas: morals and criticism
regard our tastes and sentiments: and politics consider men as united in society, and dependent on
each other. In these four sciences of Logic, Morals, Criticism, and Politics, is comprehended almost
everything, which it can any way import us to be acquainted with, or which can tend either to the
improvement or ornament of the human mind.

Here then is the only expedient, from which we can hope for success  in our philosophical
researches, to leave the tedious lingering method, which we have hitherto followed, and instead of
taking now and then a castle or village on the frontier, to march up directly to the capital or center
of these sciences, to human natur e itself; which being once masters of, we may every where else
hope for an easy victory. From this station we may extend our conquests over all those sciences,
which more intimately concern human life, and may afterwards proceed at leisure to discover more
fully those, which are the objects of pore curiosity. There is no question of importance, whose
decision is not compriz'd in the science of man; and there is none, which can be decided with any
certainty, before we become acquainted with that science. In  pretending, therefore, to explain the
principles of human nature, we in effect propose a compleat system of the sciences, built on a
foundation almost entirely new, and the only one upon which they can stand with any security.

And as the science of man isthe -only solid foundation for the other sciences, so the only solid
foundation we can (live to this science itself must be laid on experience and observation. 'Tis no
astonishing reflection to consider, that the application of experimental philosophy to m oral subjects
should come after that to natural at the distance of above a whole century; since we find in fact, that there was about the same interval betwixt the origins of these sciences; and that reckoning from
THALES to SOCRATES, the space of time is  nearly equal to that betwixt, my Lord Bacon and
some late philosophers in England, who have begun to put the science of man on a new footing, and
have engaged the attention, and excited the curiosity of the public. So true it is, that however other
nationsmay rival us in poetry, and excel us in some other agreeable arts, the improvements in
reason and philosophy can only be owing to a land of toleration and of liberty.

Nor ought we to think, that this latter improvement in the science of man will do less  honour to our
native country than the former in natural philosophy, but ought rather to esteem it a greater glory,
upon account of the greater importance of that science, as well as the necessity it lay under of such a reformation. For to me it seems evide nt, that the essence of the mind being equally unknown to us
with that of external bodies, it must be equally impossible to form any notion of its powers and
qualities otherwise than from careful and exact experiments, and the observation of those particul ar
effects, which result from its different circumstances and situations. And tho' we must endeavour to
render all our principles as universal as possible, by tracing up our experiments to the utmost, and
explaining all effects from the simplest and fewestcauses, 'tis still certain we cannot go beyond
experience; and any hypothesis, that pretends to discover the ultimate original qualities of human
nature, ought at first to be rejected as presumptuous and chimerical.

I do not think a philosopher, who woul d apply himself so earnestly to the explaining the ultimate
principles of the soul, would show himself a great master in that very science of human nature,
which he pretends to explain, or very knowing 'm what is naturally satisfactory to the mind of man.
For nothing is more certain, than that despair has almost the same effect upon us with enjoyment,
and that we are no sooner acquainted with the impossibility of satisfying any desire, than the desire
itself vanishes. When we see, that we have arrived at the utmost extent of human reason, we sit
down contented, tho' we be perfectly satisfied in the main of our ignorance, and perceive that we
can give no reason for our most general and most refined principles, beside our experience of their
reality; which is  the reason of the mere vulgar, and what it required no study at first to have
discovered for the most particular and most extraordinary phaenomenon. And as this impossibility
of making any farther progress is enough to satisfy the reader, so the writer may derive a more
delicate satisfaction from the free confession of his ignorance, and from his prudence in avoiding
that error, into which so many have fallen, of imposing their conjectures and hypotheses on the
world for the most certain principles. When this mutual contentment and satisfaction can be
obtained betwixt the master and scholar, I know not what more we can require of our philosophy.

But if this impossibility of explaining ultimate principles should be esteemed a defect in the science
of man, I  will venture to affirm, that 'tie a defect common to it with all the sciences, and all the arts,
in which we can employ ourselves, whether they be such as are cultivated in the schools of the
philosophers, or practised in the shops of the meanest artizans.None of them can go beyond
experience, or establish any principles which are not founded on that authority. Moral philosophy
has, indeed, this peculiar disadvantage, which is not found in natural, that in collecting its
experiments, it cannot make them purposely, with premeditation, and after such a manner as to
satisfy itself concerning every particular difficulty which may be. When I am at a loss to know the
effects of one body upon another in any situation, I need only put them in that situation, and observe

what results from it. But should I endeavour to clear up after the same manner any doubt in moral
philosophy, by placing myself in the same case with that which I consider, 'tis evident this reflection
and premeditation would so disturb the operationof my natural principles, as must render it
impossible to form any just conclusion from the phenomenon. We must therefore glean up our
experiments in this science from a cautious observation of human life, and take them as they appear
in the common courseof the world, by men's behaviour in company, in affairs, and in their
pleasures. Where experiments of this kind are judiciously collected and compared, we may hope to
establish on them a science which will not be inferior in certainty, and will be much su perior in
utility to any other of human comprehension. MsSVig