• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

Thus, objections like: Under a Humean account, the toddler who burned his hand would not fear the flame after only one such occurrence because he has not experienced a constant conjunction, are unfair to Hume, as the toddler would have had thousands of experiences of the principle that like causes like, and could thus employ resemblance to reach the conclusion to fear the flame. As we experience enough cases of a particular constant conjunction, our minds begin to pass a natural determination from cause to effect, adding a little more "oomph" to the prediction of the effect every time, a growing certitude that the effect will follow again. Nevertheless, ‘causation’ carries a stronger connotation than this, for constant conjunction can be accidental and therefore doesn’t get us the necessary connection that gives the relation of cause and effect its predictive ability. We may therefore now say that, on Hume’s account, to invoke causality is to invoke a constant conjunction of relata whose conjunction carries with it a necessary connection.

Hume argues that we cannot conceive of any other connection between cause and effect, because there simply is no other impression to which our idea may be traced. For instance, a horror movie may show the conceivability of decapitation not causing the cessation of animation in a human body. Hume challenges us to consider any one event and meditate on it; for instance, what is billiards a billiard ball striking another. What is meant when some event is judged as cause and effect? Hume therefore recognizes cause and effect as both a philosophical relation and a natural relation, at least in the Treatise, the only work where he draws this distinction. Natural relations have a connecting principle such that the imagination naturally leads us from one idea to another. But to proffer such examples as counter to the Copy Principle is to ignore the activities of the mind. Instead, the impression of efficacy is one produced in the mind.

Of the common understanding of causality, Hume points out that we never have an impression of efficacy. There are reams of literature addressing whether these two definitions are the same and, if not, to which of them Hume gives primacy. In the Treatise, Hume identifies two ways that the mind associates ideas, via natural relations and via philosophical relations. The three natural relations are resemblance, contiguity, and cause and effect. But cause and effect is also one of the philosophical relations, where the relata have no connecting principle, instead being artificially juxtaposed by the mind. And here it is important to remember that, in addition to cause and effect, the mind naturally associates ideas via resemblance and contiguity. The relation of cause and effect is pivotal in reasoning, which Hume defines as the discovery of relations between objects of comparison. There is nothing in the cause that will ever imply the effect in an experiential vacuum. For Hume, the necessary connection invoked by causation is nothing more than this certainty. It is the internal impression of this "oomph" that gives rise to our idea of necessity, the mere feeling of certainty that the conjunction will stay constant. Because of this, our notion of causal law seems to be a mere presentiment that the constant conjunction will continue to be constant, some certainty that this mysterious union will persist.

Ergo, the idea of necessity that supplements constant conjunction is a psychological projection. In addition to its accounting for the necessity of causation mentioned above, recall that Hume makes frequent reference to both definitions as accurate or just, and at one point even refers to D2 as constituting the essence of causation. Strictly speaking, for Hume, our only external impression of causation is a mere constant conjunction of phenomena, that B always follows A, and Hume sometimes seems to imply that this is all that causation amounts to. We must therefore follow a different route in considering what our impression of necessity amounts to. What is this necessity that is implied by causation? The realist interpretation then applies this to Hume’s account of necessary connection, holding that it is not Hume’s telling us what causation is, but only what we can know of it. Having approached Hume’s account of causality by this route, we are now in a position to see where Hume’s two definitions of causation given in the Treatise come from. Stathis Psillos, for instance, views Hume’s inductive skepticism as a corollary to his account of necessary connection. Rather, we can use resemblance, for instance, to infer an analogous case from our past experiences of transferred momentum, deflection, and so forth.