Hume's Theory of Causation and its Epistemological Premise

ヒュームの因果論は,伝統的因果律に対する批判から始まる.因果性は絶対的知識でなく,蓋然性にすぎないとする彼の結論は,全ての観念は印象に由るとする認識論的前提に立つものであるが,因果結合における必然性の観念の起源をも印象に求めようとする彼の意図を思想的背景から探索したい.As B. Russell says, the modern philosophy of causation begins with Hume. Before Hume the relation of causation had been more or less assimilated to that of ground and consequent in logic, but this, as Hume rightly perceived, was a mistake. Hume found that the relation of causation is not a logical Relation of Ideas, but a relation of the Matters of Facts wich are known through experience. Hume says that all perceptions of human mind resolve themselves into "Impressions and Ideas", and he insists that all ideas have their origin in some impression. Therefore, according to this epistemological premise, the idea of necessary connection which is the essence of causation, must come from such an impression as causes the idea. But, of course, no impression of necessary connection is to be found in experience, because, as Hume himself declares, necessity is something which exists in mind, not in objects. Hume well knows that necessity is only in mind, and yet seeks its impression. This seems to be a contradiction in his argument. In this discrepant insistence, however, we guess Hume's hidden purpose to make it clear that we must not refer necessity to any unknown quality of objects, but rather seek it in apparent relation between objects. This thought should be called positivism, rather than phenomenalism. From this point of view, causation is definable only in terms of sequence, and can not attain to an absolute knowledge, but only to probability. But frequently repeated observation of constant conjunction produces a Custom of association of ideas in mind, and makes a belief about relation of cause and effect. So, Hume concludes that causation is nothing but association of ideas. Association of ideas is, however, a very deterministic theory of psychology which depends upon causal law. In this point, Hume is condemned for committing a self-contradiction in the construction of his theory. It is true that throughout the whole system of Hume's causal theory, there are no little incompleteness and inconsistency. And yet we must admit Hume made a great contribution in removing superstitious prejudices and advancing scientific research of natural laws since he brought the old problem of causation into the field of experience and gave it a subjectivistic reconsideration