Kant’s Solution to Hume’s Problem

Kant aims to put metaphysics on a firm footing to make it a science in his Critique of Pure Reason. However, Hume’s attack on cause and effect suggests metaphysics is not possible. Hence Kant needs to solve the Humean challenge.

In Kant’s account from Prolegomena, Hume proves that reason alone cannot show the connection between cause and effect.[1] This is because the connection requires cause to lead necessarily to an associated effect. It is only out of “habit” that such an association is made, when an observer having previously seen a billiard ball strike another, expects the struck ball to move.[2] Hume questions wherein lies the cause and effect when all that is observed is “contiguity in time and place”, “priority in time” and “constant conjunction.”[3]

Kant sees Hume’s attack on cause and effect as an attack on the entire project of metaphysics. When Hume’s objection is generalised, “the concept of the connection of cause and effect is far from being the only concept through which the understanding thinks connections of things a priori; rather metaphysics consists wholly of such concepts.”[4] However, Kant believes Hume’s conclusion to be “premature and erroneous,”[5] though still a challenge of “sufficient value” to wake him from his “dogmatic slumber” and change his path in philosophy.[6] Since Kant aims to give metaphysics a strong foundation, he needs to solve Hume’s problem.

His solution follows: when one appearance is followed always by another, an observer can use “hypothetical judgement”[7] to relate the two appearances. For this subjective connection of perceptions to become an experience, the connection must be necessary and universally valid. To make it so, the empirical connection is restated as a law of causation, valid not only for appearances but also for possible experiences. The concept of cause necessarily belongs to the “form of experience”[8] unifying the perceptions.

Such a concept and other pure concepts of the understanding only have meaning when related to experience. These concepts “spell out appearances, so that they can be read as experience”[9] to help us understand the connections between the appearances. Hence, the pure concepts of the understanding are a priori, that is, prior to experience. However, their uses are restricted only to experience because they are “founded solely in the relation of the understanding to experience.”[10] Importantly, they are not derived from experience, but rather, “experience is derived from them.”[11] We need the concept of causation to understand our experiences – we derive our experiences with the help of the concept of causation; otherwise we are only left with “arbitrary connections.”[12]

Kant notes that this inversion of the connection between our understanding and experience is something that would never occur to Hume.[13] As a radical empiricist, Hume views experience as the source of all ideas with none being innate.[14] Kant effectively turns Hume’s problem on its head – it is not experience that drives our understanding. Instead, appearances are interpreted through the frame in our minds of the pure concepts of the understanding, giving us understanding of our experiences.

Bibliography

Hume, David. A Treatise of Human Nature. Edited by L. A. Selby-Bigge and P. H. Nidditch. Oxford: Oxford University Press, 1978.

Kant, Immanuel. “Prolegomena to Any Future Metaphysics That Will Be Able to Come Forward as Science (1783).” In Theoretical Philosophy after 1781, translated by Gary Hatfield, 29–170. Cambridge: Cambridge University Press, 2002.

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[1] Immanuel Kant, “Prolegomena to Any Future Metaphysics That Will Be Able to Come Forward as Science (1783),” in Theoretical Philosophy after 1781, trans. Gary Hatfield, The Cambridge Edition of the Works of Immanuel Kant (Cambridge: Cambridge University Press, 2002), 257–58.

[2] David Hume, A Treatise of Human Nature, ed. L. A Selby-Bigge and P. H Nidditch (Oxford: Oxford University Press, 1978), 652.

[3] Ibid., 649.

[4] Kant, Prolegomena, 260.

[5] Ibid., 258.

[6] Ibid., 260.

[7] Ibid., 312.

[8] Ibid.

[9] Ibid.

[10] Ibid., 313.

[11] Ibid.

[12] Ibid.

[13] Ibid.

[14] Hume, Treatise of Human Nature, 647–48.