Hume's Problem of Induction

Patrick Brissey exposes a major unprovable assumption at the core of science.

- Patrick Brissey 

Will the sun rise tomorrow? The answer seems simple: an emphatic “Yes!” But how do you know? We can imagine the following commonsense response: “Well, every morning, the sun rises; atleast from my perspective. Wait until tomorrow; you’ll see!” The reasoning is that, based on past observations, we know that the sun will more than likely rise in the morning. Notice that this conclusion is not certain: the argument is not a purely logical deduction. There are, after all unlikely science fiction scenarios where the sun is suddenly destroyed. These scenarios show that the claim the sun will rise in the morning is possibly false. Despite this, there seems to be a very good probability that it will rise.

In his Enquiry Concerning Human Understanding (1748), David Hume (1711-1776) asserts that even this argument is not good. Hume thinks the skeptical answer – ‘We Don’t Know!’ – is the logical response to this sort of inductive (past-experience-based) argument. For him, we ought to withhold belief on inductive assertions about the future, even over such likely questions as whether the sun will rise in the morning. But perhaps this does not seem right to you: We all know that the sun will rise in the morning, don’t we?

Let’s see how Hume gets to his conclusion.

The ‘Future Will Resemble the Past’ Principle

Imagine someone playing a game of pool. She hits the cue ball, and it collides with the eight ball. What should happen next?

Based on past experience, one would think that the eight ball will travel in a straight line away from the cue ball until impeded by another object. But this is only one hypothesis. Consider the following alternative hypotheses: