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Wednesday, December 29, 2004



david hume developed the empiricism of locke and berkeley to its logical extreme end, and in making it consistent also made it incredible. his treatise on human nature (1734-7) went unnoticed at publication, but was edited into inquiry into human understanding, which so influenced kant. he befriended the somewhat mad rousseau in 1763, and suffered a typically romantic falling out instigated by him. he was a moderate, mild and temperate man, in success and disappointment.

refutation of substance

hume, in treatise, holds that all "ideas" consist of "impressions" (precepts), and even complex ideas are constituted only of simple impressions. abstract ideas "are nothing but particular ones, annexed to a certain term, which gives them a more extensive significance and makes them recall upon occasion other individuals, which are similar to them." this is nominalism, and can be criticized in hume for ignoring vagueness (he posits ideas are derived from impressions they exactly, not closely, represent).

hume refutes the idea of the self because one cannot get an impression of the self -- the self is instead always holds a perception other than itself which cannot be got rid of, and really cannot be perceived except as a bundle of impressions. if there is a "soul" or a "substance" of the self, we cannot have an idea of it.

the problem of induction

the section titled "of knowledge and probability" deals with uncertain knowledge -- that drawn by induction from observation, which includes all our knowledge of the future and the unobserved. he identifies seven philosophical relations of two kinds: those which depend on ideas (these are resemblance, contrariety, degrees in quality and numbers in quantity) which yield certain knowledge; and those which depend not only on ideas (identity, relations of time and place, causal) which yield only probable knowledge. of these, identity and spatio-temporal relations are immediate sensory impressions -- leaving causation alone to infer one thing or occurence from another, beyond what can be perceived. it had previously (scholasticism, descartes) been supposed that causation was necessary, as a logical relation, when B followed A.

hume observes that the power of A to cause B cannot be discovered in reasoning on the ideas of A and B alone, nor of experiencing A followed by B, but only by the experience of the repeated conjunction of A and B -- so that the impression of A leads us to the idea of B.

but this, he notes, cannot offer the mechanism by which A causes B. "belief", hume asserts, is this idea -- we believe A and B to be connected, even though this is unevidenced. what we believe to be the connection of objects is only the connection of the ideas of the objects, a determination formed in the mind.

this can be said: 1) in causation, there is no indefinable relation except conjunction or succession; 2) induction by enumeration is not a valid form of argument. hume says that there is not the slightest rational reason to expect the sun to rise tomorrow morning, even though it has risen every morning; there is only habit.

this is the hume's rejection of the principle of induction -- which is, if A is very often conjoined with B, no instance of A not being accompanied or followed by B is known, then it is probable that, when A is next observed, it will be accompanied or followed by B.

this is a very skeptical viewpoint -- in essence, belief is never rational because we know nothing, that there is no point to philosophy or science. hume himself, having produced this, advocates some measure of "carelessness and inattention" as a means of functioning in the world.

some criticize hume by saying that we can in fact perceive some causal relationships. in the physical sciences, however, hume is entirely correct -- "A causes B" is invariably a highly complex series of events which cannot be perceived. in psychology, hume's critics claim to observe causation, as pain causing a cry; however, physiology too is extremely complicated and unperceived.

it can also be said that, if the non-empirical logical principle of induction is accepted, empiricism -- the philosophy that all knowledge is based on experience -- can proceed. this is a serious departure from pure empiricism, but makes science valid.


russell writes:
hume's philosophy, whether true or false, represents the bankruptcy of 18th century reasonableness. he starts out, like locke, with the intention of being sensible and empirical, taking nothing on trust, but seeking whatever instruction is to be obtained from experience and observation. but having a better intellect than locke's, a greater acuteness in analysis, and a smaller capacity for accepting uncomfortable inconsistencies, he arrives at the disastrous conclusion that from experience and observation nothing is to be learnt.
hume, having eviscerated rationality, was followed by rousseau, who found belief of the heart superior to reason. kant and hegel, who attempted rational arguments refuting hume, were unsuccessful; the philosophers impervious to hume are those who are not rational -- rousseau, schopenhauer, nietzsche. unreason has grown even since hume.

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