David Hume and Empiricism

March 24, 2025

David Hume is an empiricist who believes that all of our knowledge stems from experience. I did a summary of parts of his book here.

There are two interesting results from this paper that lead to an intriguing interpretation. The first result is that believing in induction—reasoning based on experience (as opposed to deduction, which is reasoning based on our mind alone, like in mathematics, where you don’t need sensory experiences)—is unjustified. That is a wild claim because we rely on induction all the time in our daily lives: the cereal is empty, so someone must have eaten it; my street is blocked, so there must have been an accident; my room looks trashed, so someone must have come in and done it. All these, and many more, are examples of induction. Yet Hume argues that believing in induction is completely unjustified, and I think his book presents this argument quite convincingly.

The second result is that we are unjustified in believing that cause and effect will hold in the future. This means we can’t know that, in a few minutes, gravity won’t suddenly invert and make everything fly upward for no reason, or that a unicorn won’t suddenly appear in front of us.

Both the rejection of induction and the uncertainty of cause and effect follow directly from Hume’s empiricism. However, these conclusions seem so counterintuitive—so absurd—that this can be interpreted as an example of reductio ad absurdum: if a theory leads to absurd results, then the theory itself must be flawed.

In a way, by highlighting these positions and their absurdity, Hume undermines his own philosophy—reducing it to the absurd and untenable.

What is Hume’s response to this? Not my problem. Instead of reconsidering whether this might invalidate empiricism, he simply accepts it.