David Hume: Lecture one
Life and Work
1711: Born at Edinburgh, May 7 (=26 April, old style).
1730s: After studying at Edinburgh University, spends time in Bristol and France,
composing A Treatise of Human Nature in the latter and completing it in 1736.
Publishes the Treatise in two parts, in 1739–1740. It doesn’t make much of an
impact:
Never literary attempt was more unfortunate than my Treatise of Human Nature. It fell deadborn from the press, without reaching such distinction, as even to excite a murmur among the
zealots. But being naturally of a cheerful and sanguine temper, I very soon recovered the
blow, and prosecuted with great ardour my studies in the country. (‘My Own Life’)
1740s: Applies for professorship at Edinburgh, but is rejected (though he does
subsequently get a job in the library). Publishes essays on various topics, then
An Enquiry concerning Human Understanding in 1748 and An Enquiry
concerning the Principles of Morals in 1751. These enquiries cover much of
the same ground as the Treatise (particularly its first and third books
respectively), but they omit certain discussions, and a prefatory note
comments:
Henceforth, the Author desires, that the following Pieces may alone be regarded as containing
his philosophical sentiments and principles.
1750s: Writes The History of England, from the Invasion of Julius Caesar to the
Revolution in 1688, his greatest popular success and the standard work on the
subject for many decades. Also composes his Dialogues concerning Natural
Religion, though these are only published posthumously in 1779.
1760s: Spends time in Paris, becoming known and admired by Voltaire, Rousseau et
al.
1776: Dies at Edinburgh, August 25.
A general overview of Hume’s philosophy
Hume is often presented as being simply a continuation of the empiricist current of
Locke and Berkeley, but it is worth noting what he himself says about his influences
and affinities:
I shall submit all my Performances to your Examination, & to make you enter into them more
easily, I desire of you, if you have Leizure, to read once over le Recherche de la Verité of
Pere [Nicolas] Malebranche, the Principles of Human Knowledge by Dr Berkeley, some of the
more metaphysical Articles of Baile’s [Pierre Bayle’s] Dictionary; such as those of Zeno, &
Spinoza. Des-Cartes Meditations wou’d also be useful, but I don’t know if you will find it
easily among your Acquaintances. These Books will make you easily comprehend the
metaphysical Parts of my Reasoning. And as to the rest, they have so little Dependence on all
former Systems of Philosophy, that your natural Good Sense will afford you Light enough to
judge of their Force & Solidity. (Letter to Michael Ramsay, 26 Aug. 1737).
One thing that sets Hume apart from his predecessors—both the rationalists and the
earlier empiricists—is that he has little interest in making normative claims about
what we ought to believe. For instance, a rationalist like Descartes would attempt to
demonstrate that we should believe in the mind-independent existence of body; an
empiricist like Berkeley would attempt to demonstrate that we should not. But, as far
as Hume is concerned, that question is irrelevant: the fact is that we do believe this,
and that’s all that really counts.
Hume’s approach to metaphysics and epistemology might be compared to the
approach he takes to ethics. Of the latter, he writes:
In every system of morality, which I have hitherto met with, I have always remark’d, that the
author proceeds for some time in the ordinary way of reasoning, and establishes the being of a
God, or makes observations concerning human affairs; when of a sudden I am surpriz’d to
find, that instead of the usual copulations of propositions, is, and is not, I meet with no
proposition that is not connected with an ought, or an ought not. This change is imperceptible;
but is, however, of the last consequence. For as this ought, or ought not, expresses some new
relation or affirmation, ’tis necessary that it shou’d be observ’d and explain’d; and at the same
time that a reason should be given, for what seems altogether inconceivable, how this new
relation can be a deduction from others, which are entirely different from it. (Treatise, book 3,
part 1, section 1).
In Hume’s opinion, there is no valid deduction from the way things are to any
conclusion about how things ought to be. Consequently, Hume’s ethical works are
purely descriptive, analysing empirically how our moral sentiments arise within us,
but never presuming to judge whether these are, in any absolute sense, the right
sentiments for us to have. Likewise in epistemology, he traces the origins of certain
classes of universally-held beliefs, but he does not offer a judgment about whether we
are, in any absolute sense, correct in holding such views. We can’t help but hold them
anyway, so the question of correctness or incorrectness is just as redundant as it is
unanswerable.
Hume subtitled the Treatise, ‘An Attempt to introduce the experimental Method of
Reasoning into Moral Subjects’. He was very enthusiastic about the new science, and
Newtonianism in particular, and he wanted to establish an analogous ‘Science of
Man’.
’Tis evident, that all the sciences have 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 they lie under the cognizance of men, and are judged
of by their powers and faculties. (Treatise, Introduction).
In somewhat the same way as Newton had laid out the laws whereby gravity operated,
while at the same time stubbornly refusing to answer the question of what it was that
was operating in this way—on the grounds that the experimental evidence was silent
on that issue—Hume wants to describe the structure of human cognition, but to go no
further than that.
In general terms, he feels that there are two main elements that, between them, work
to generate our natural beliefs and judgments. Experience is certainly one of these,
and an essential one too—hence the standard classification of Hume as an
empiricist—but there is also another. Most of our beliefs about the world, for Hume,
are not simply derived from our experience thereof. But then, on the other hand, they
do not result from our intellectual faculties either, even in conjunction with that
experience. Rather, they result out of the way the passionate side of human nature is
disposed to respond to experience. Hume regards human beings as fundamentally
governed by instincts and habits, little different from animals.
the experimental reasoning itself, which we possess in common with beasts, and on which the
whole conduct of life depends, is nothing but a species of instinct or mechanical power, that
acts in us unknown to ourselves; and in its chief operations, is not directed by any such
relations or comparisons of ideas, as are the proper objects of our intellectual faculties.
Though the instinct be different, yet still it is an instinct, which teaches a man to avoid the
fire; as much as that, which teaches a bird, with such exactness, the art of incubation, and the
whole economy and order of its nursery. (Enquiry, sect. 9).
The beliefs that we form will indeed extend beyond what the raw data of experience
themselves reveal: but we have no rational justification for extending our judgments
in this way, a justification of the kind that might indicate that we are right thus to
extend them. It is just a matter of fact that such a passionate impulse does exist within
us, common to all people and constitutive of human nature as such. On the other hand,
reason will not suggest that there is anything wrong with our thus extending our
judgments either: it is simply silent on the issue. Hume feels that it is a mistake to
suppose that pure reason can ever discover any matters of fact at all, whether positive
or negative. Rather,
Reason is, and ought only to be the slave of the passions, and can never pretend to any other
office than to serve and obey them. (Treatise, bk. 2, pt. 3, sect. 3).
Although Hume does present plenty of rational arguments in the course of his
discussion, their goal is simply to show the impotence of reason itself, when dealing
with concrete matters of fact (as opposed to purely abstract ‘relations of ideas’, such
as mathematical principles). Any attempt to live according to the dictates of pure
reason will be self-defeating, for rational argument, if pushed to its ultimate
conclusion, can yield only a thoroughly impractical scepticism. Ultimately, Hume is
pretty down on philosophy as it had traditionally been practiced. He does like
mathematics, which is rational but which tells us nothing about the real world. He also
likes natural science, which does tell us about the world but which is neither rational
nor irrational—it is simply a more careful and regimented version of what our nonrational passions and impulses drive us all to do anyway. But that is all that he has any
real sympathy for:
When we run over libraries, persuaded of these principles, what havoc must we make? If we
take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does
it contain any abstract reasoning concerning quantity or number? No. Does it contain any
experimental reasoning concerning matter of fact and existence? No. Commit it then to the
flames: for it can contain nothing but sophistry and illusion. (Closing words of the Enquiry).
Impressions and Ideas (Enquiry, sect. 2; Treatise, bk. 1, pt. 1, sect. 1)
Hume subdivides perceptions into two categories: ‘impressions’ and ‘ideas’. Roughly
speaking, impressions are the vivid perceptions that we receive in actual occurrent
experience, such as when an external body acts upon our sense-organs, while ideas
are the fainter copies of these that we subsequently form for ourselves in the
imagination or dredge up from the memory. But Hume doesn’t want to presuppose
anything about the origins of these perceptions, so instead he defines the distinction
simply in terms of what they carry with them on the surface, namely their respective
degrees of force and vivacity. Any forceful, lively, vivid, clear perception thereby
qualifies as an ‘impression’; any fainter, weaker perception qualifies as an ‘idea’.
Hume’s fundamental epistemological principle is that no idea can possess any content
beyond what has already been received in prior impressions. This is supposed to be an
empirical claim, rather than a conceptual one. There is certainly no logical reason why
a faint idea shouldn’t just spontaneously appear in the mind, despite failing to
resemble any earlier vivid impressions. But Hume believes that, just as a matter of
fact about how human psychology develops over time, we simply do not encounter
cases like that.
Hume addresses the ‘innate ideas’ debate, which some might regard as central to the
‘empiricist’/‘rationalist’ division, but he regards that whole debate as being, frankly,
just a bit of verbal trifling. In one corner, we have Locke, who claims that ideas do not
precede experience. But then, in the other corner, there is Leibniz, who also claims
that (actual) ideas do not precede experience (even though those ideas might
nevertheless exist in a state of latent potentiality before they are eked out into
conscious actuality by experiential stimuli). As far as Hume is concerned, the thing
that both Leibniz and Locke can happily agree on is with that all ideas (defined in his
way, as weaker perceptions) are posterior to corresponding impressions (defined
simply as stronger ones).
Hume does, however, identify an apparent counter-example to his own thesis.
Imagine someone who has experienced every shade of blue, from the lightest to the
darkest, apart from just one specific shade in the middle of the spectrum. Won’t he be
able to use his imagination to fill in the gap, and figure out for himself what that
missing shade of blue would look like? Hume acknowledges that he probably could
do this. But this presents a problem for the general principle, because this person has
neither had an impression of that particular shade, nor could he apparently form an
idea of it by mentally dissecting the impressions of those other shades that he has
experienced, and recombining their elementary parts in new ways (because
impressions of colours would seem to be simple, without any component parts).
However, Hume doesn’t let this apparent counter-example trouble him too much: ‘this
instance is so singular, that it is scarcely worth our observing, and does not merit that
for it alone we should alter our general maxim.’
Association of Ideas
Having thus classified the contents of our minds, Hume then proceeds to describe how
such perceptions can be related to one another. In the Treatise (bk. 1, pt. 1, sect. 5), he
enumerates seven kinds of relation between ideas: resemblance, identity, spatiotemporal relations (distance, contiguity, etc.), relations of quantity, relations of
quality, contrariety, and causal connections. But, at least as far as substantive facts
about the world are concerned, he feels that these can be reduced to just three main
heads: resemblance, contiguity, and causality. An idea or impression of one thing
might stir up an idea of something else that resembles the first thing in some salient
way (‘A picture naturally leads our thoughts to the original’). A perception of
something might prompt the mind to think of something else in the same place as it
(‘the mention of one apartment in a building naturally introduces an enquiry or
discourse concerning the others’). Or, again, a perception of something might lead the
mind to turn to the customary cause or effect of things of that sort (‘and if we think of
a wound, we can scarcely forbear reflecting on the pain which follows it’—Enquiry,
sect. 3).
Hume compared the centrality of these three associations of ideas, in any adequate
account of human cognition, to the centrality of the gravitational force in any
adequate account of physics. ‘Here is a kind of attraction, which in the mental world
will be found to have as extraordinary effects as in the natural, and to shew itself in as
many and as various forms.’ (Treatise, bk. 1, pt. 1, sect. 4). As we will see in detail as
we go on, Hume felt that these associations played absolutely central roles in the
establishment of various concepts that had been regarded as defining the traditional
subject-matter of metaphysics: mind, body, causation, etc. And Hume did not reject
these topics out of hand, but what he did feel was that the traditional philosophical
approach to them had been misguided. Our rational powers, he felt, simply were not
capable of giving us epistemological access to any kind of absolute truth on such
matters, as traditional metaphysicians had hoped that they might be. Instead, the
proper approach to topics like these, the only approach that had a chance of yielding
any solid results, would be to examine how we came to develop such ideas in the first
place—and Hume’s answer would be drawn up in terms of these three associations.