So far the history of the philosophy of the eighteenth century has been
the story of the empirical attempt to solve the Cartesian problem by
reducing mind to matter, and of the idealistic attempt to solve the
same problem by reducing matter to mind. There remains one more phase
of eighteenth century speculation, namely, Hume's answer to the
Cartesian problem, if indeed it may be called an answer, since it is
rather a denial of the reason for proposing such a problem at all. For,
instead of trying to untie what may be called the Gordian knot of
post-Cartesian speculation, Hume cut the knot by denying the substantial
existence of mind and matter.
HUME
Life. David Hume was born at Edinburgh in 1711. After an
unsuccessful attempt to fit himself for the profession of law, he
decided to take up the study of philosophy and literature. During the
years 1734 to 1737, which he spent in France, he wrote his Treatise
on Human Nature. The work, he says, "fell dead-born from the press,
without reaching such distinction as even to excite a murmur among the
zealots." Later, he recast the first book of the Treatise into his
Enquiry concerning Human Understanding, the second book into his
Dissertation on the Passions, and the third into his Enquiry
concerning the Principles of Morals. His Essays, Moral,
Political, and Literary, which were published at Edinburgh in 1742,
met a favorable reception. In 1747 he accompanied a military embassy to
the courts of Vienna and Turin, and again in 1763 he accompanied the
English ambassador to the court of Versailles, where he remained until
1766. During the interval he had held the office of keeper of the
Advocates' Library at Edinburgh, and had begun the publication of his
History of England. In 1767 he was made under-secretary of state
in the Foreign Office. In 1769 he returned to Edinburgh, and died there
in 1776.
Sources. In addition to the works already mentioned Hume wrote a
Natural History of Religion and Dialogues concerning Natural
Religion. The standard edition of Hume's philosophical works is that of Green
and Grosse, 4 vols., London, 1874, reprinted 1889-1890. The student may
be referred to Huxley's Hume (English Men of Letters
series, 1879), to Knight's Hume (Blackwood's Philosophical
Classics, 1886), and to the Introduction to Green and
Grosse's edition of Hume's Works.
DOCTRINES
Starting Point. Hume's starting point is that of the empiricist,
and his conception of the method of philosophical procedure is that of
the critical philosopher. In the Introduction to the Treatise on
Human Nature he writes, "To me it seems evident 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 . . . it is
certain we cannot go beyond experience." [1] The critical element
appears when, in this same Introduction and in the opening paragraphs
of the Enquiry concerning Human Understanding, he reduces all
philosophy to the study of human nature, basing the study of human
nature on the observation of mental phenomena and "an exact analysis of
the powers and capacity" of the mind.
[1] Works, I, 308. References are to Green and Grosse's edition,
1890.
Analysis of Mind. According to Hume, the mind is its
contents. His analysis of the mind is, therefore, merely an
inventory of the contents of the mind, or of perceptions. In
Hume's philosophy, perception is synonymous with state of
consciousness, the term being equivalent to the Cartesian
thought and to the idea of Locke and Berkeley.
Hume divides perceptions into two classes: impressions, which
are defined as the more lively perceptions experienced when we hear,
see, will, love, etc. (perceptions therefore, include passions and
emotions as well as sensations), and ideas or thoughts, which
are faint images of impressions. [2] As to the innateness
of impressions and ideas, Hume says that, if by innate we mean
contemporary with our birth, the dispute seems to be frivolous; but if
by innate we understand what is original or copied from no
precedent perception, then we may assert that all our impressions
are innate and our ideas not innate. [3] When, therefore, Hume
speaks of memory, imagination, ideas of relation, abstract ideas, etc.,
he is speaking of mental faculties and states which are ultimately
reducible to sense-faculties and to the impressions of the senses.
[2] Op. cit., IV, 13.
[3] Note to the second edition of the Enquiry,
Works, IV, 17.
What, then, are the objects of our impressions? Hume answers that we do
not perceive substance nor qualities, but only our own subjective
states. "'T is not our body we perceive when we regard our limbs and
members, but certain impressions which enter by the senses. The
last words seem to indicate a belief in an external cause of our
impressions, and, indeed, Hume is not at all consistent in his
subjectivism; for he admits, in at least one passage, the possibility
of our impressions either arising from the object, or being produced by
the creative power of the mind, or being derived from the Author of our
being.
The denial of the substantiality of the mind is Hume's most
distinctive contribution to psychology. It is, he says, successive
perceptions only that constitute the mind. The substantiality of the
ego is a delusion; what we call mind is simply "a heap or collection of
different perceptions united together by certain relations, and
supposed, though falsely, to be endowed with simplicity and
identity." [4] Thus did Hume complete the work of empiricism. Locke
reasoned away everything except the primary qualities of bodies and the
unknown substratum (substance) in which they adhere; Berkeley showed
that even the substance and primary qualities of bodies might be
reasoned away, and now Hume applies the same solvent to the substance
of mind itself, and leaves nothing but phenomena.
[4] Cf.Works, I, 534.
If the substantial nature of the ego is a delusion, immortality is
not a datum of reason. We are not surprised, therefore, to find
that in the essay On the Immortality of the Soul, Hume, after
examining the arguments in favor of immortality, which arguments he
divides into metaphysical, moral, and physical, concludes that "it is
the gospel, and the gospel alone, that has brought life and immortality
to light."
Analysis of Causation. Quite in keeping with Hume's denial of
substance is his analysis of causation into a succession of phenomena.
All our ideas, he teaches, are connected either by resemblance,
contiguity in time, contiguity in space, or causality. Causality,
then, is merely a relation between our ideas; but is it an a
priori relation, and if not, whence and how does it arise?
The first of these questions Hume answers in the negative. He
formulates the principle of causality as follows: Whatever event
has a beginning must have a cause. [5] He maintains that "the knowledge
of this relation (causality) is not, in any instance, attained by
reasonings a priori; but arises entirely from experience, when
we find that any particular objects are constantly conjoined
with each other. [6] All distinct ideas are separable from each other,
and, as the ideas of cause and effect are evidently distinct, 't will
be easy for us to conceive any object as non-existent this moment, and
existent the next, without conjoining to it the distinct idea of a
cause or producing principle." [7] The argument, as Huxley remarks,[8]
"is of the circular sort, for the major premise that all distinct ideas
are separable in thought, assumes the question at issue."
[5] Cf. Huxley's Hume, p. 120. In Hume's Treatise on
Human Nature, p. 381, Occurs the form, "Whatever has a beginning
has also a cause of existence."
[6] Works, IV, 24.
[7] Op. cit., I, 381.
[8] Hume, p. 122.
The axiom of causality, therefore, comes from experience. But, Hume
observes, one instance does not constitute sufficient experimental
evidence of the causal connection of two phenomena. When, however,
"one particular series of events has always, in all instances, been conjoined with another, we make no
longer any scruple in foretelling one on the appearance of the other. .
. . We then call the one cause and the other effect. We
suppose that there is some connexion between them: some power in the
one by virtue of which it infallibly produces the other. . . . But
there is nothing in a number of instances different from every single
instance which is supposed to be exactly similar, except only that
after a repetition of similar instances the mind is carried by
habit, upon the appearance of one event, to expect its usual
attendant and to believe that it will exist." [9] There is, therefore,
no real dependence of effect on cause, no ontological nexus, but
merely a psychological one, an expectation arising from habit or
custom.
[9] Works, IV, 62.
Hume, indeed, admits that, in addition to the notion of sequence of
phenomena, there is in our concept of causality the idea of something
resident in the cause -- a power, force, or energy -- which
produces the effect. When, however, he comes to analyze this
notion of power, he finds it to be merely a projection of the
subjective feeling of effort into the phenomenon, which is the
invariable antecedent. "No animal can put external bodies in motion
without the sentiment of a nisus, or endeavor, and every animal has a
sentiment or feeling from the stroke or blow of an external object that
is in motion. . We consider only the constant experienced conjunction
of the events, and as we feel the customary connection between
the ideas, we transfer that feeling to the objects." [10]
[10] Op. cit., IV, 62, a.
From the empirical viewpoint, Hume's analysis of the principle of
causality is thorough. If there is in the mind no power superior to
sensation and reflection, no faculty by which we are enabled to
abstract from the contingent data of sense the necessary elements of
intellectual thought, then all the axioms of science, the axiom of
causality included, are mere associations of sense-impressions. But the
empirical standpoint is erroneous; in this, as in other instances, empiricism stops where the real
problem of philosophy begins, as is evident from the fact that, while
Hume succeeds in showing that one event is connected with
another in our past experience, neither he nor any other empiricist has
shown why we are entitled to expect that events which have been
connected in the past will be connected in the future. Empiricism can
show a connectio facti, but it cannot show a connectio
juris, between antecedent and consequent, between cause and effect.
Ethics. Hume's ethical system is a development of the
fundamental doctrine of the English ethical schools of the eighteenth
century. He restricts the rôle of reason as a moral
criterion and develops the doctrine that moral distinctions are
determined by our sense of the agreeable and the disagreeable. Abstract
distinctions, mere rational intuitions or inferences, leave us
perfectly indifferent as to action, so long as they fail to acquire an
emotional value through some relation to the passions and
ultimately to the feeling of the agreeableness or disagreeableness of
the action to be performed. "Nothing but a sentiment can induce us to
give the preference to the beneficial and useful tendencies over
pernicious ones. This sentiment is, in short, nothing but
sympathy." [11] The following is the ultimate analysis of moral
value: "No man is absolutely indifferent to the happiness and misery of
others. The first has a natural tendency to give pleasure; the second,
pain. This every one may find in himself. It is not probable that these
principles can be resolved into principles more simple and universal,
whatever attempts may be made to that purpose." [12]
[11] Cf. Falckenberg, op. cit., p. 190, English trans.,
p. 233.
[12] Works, IV, 208, a.
Historical Position. Hume's philosophy is summed up in the words
pan-phenomenalism and scepticism. He reduced mind as well
as matter to mere phenomena, and denied the ontological nexus between
cause and effect. He maintained that there is no permanent, immutable
element in the world of our experience,
and that there is no valid principle which can justify metaphysical
speculation concerning the world beyond our experience. It was this
total subversion of the necessary and universal that awoke Kant from
his dogmatic slumber, and gave rise in Scotland to the movement in
favor of the philosophy of common sense.
It will be necessary, before entering on the study of these reactions
against Hume, to give a brief sketch of what is known as the German
illumination -- the transition from Leibniz to Kant.