Can you intend to do something you know you won't do?
An eccentric billionaire makes you a strange offer:
Toxin
$1,000,000
The toxin will make you painfully ill for one day, but won't cause lasting harm.
The offer: At midnight tonight, if you genuinely intend to drink the toxin tomorrow afternoon, the billionaire will deposit $1 million in your account by morning.
You don't actually have to drink it—just intend to at midnight!
Step through the puzzle and see if you can win the million:
The billionaire's scanner is reading your brain. Do you genuinely intend to drink the toxin tomorrow?
Here's the problem: You know that by tomorrow afternoon, you'll already have the money (or not). At that point, drinking the toxin gains you nothing and costs you a day of illness.
So you know you won't actually drink it. Can you genuinely intend to do something you know you won't do?
At first it seems easy: "Just intend to drink it, get the money, then change your mind!" But can you really do that?
Gregory Kavka argued that intentions are constrained by reasons, just as beliefs are constrained by evidence. Consider:
At the moment of drinking, there's zero reason to drink the toxin:
Trick yourself into genuinely believing you'll drink it. But this requires deceiving yourself about your own future behavior—is that even possible?
Make an irrevocable commitment (e.g., bet someone you'll drink it). But the puzzle specifically asks about pure intention without external constraints.
If intending to drink is rational (for the million), then drinking becomes rational too—the rationality "transfers." But does it really?
Become the kind of person who keeps intentions regardless of consequences. But can you change your character at will?
The toxin puzzle reveals something profound about the nature of intention:
We tend to think we can intend whatever we want. But intentions are mental states that must be grounded in reasons. You can't form a genuine intention to perform an action when you know you have no reason to perform it.
This has implications for:
Similarly involves a predictor who knows your choice before you make it
The value of being able to commit to future actions
Kavka developed this puzzle from deterrence theory
Can you win the money? Most philosophers think the answer is no—at least not through pure intention alone.
The puzzle exposes a fundamental limitation: we cannot simply will ourselves to intend whatever would be beneficial to intend. Our intentions must be anchored in genuine reasons for action.
Would you drink the toxin? The answer reveals something deep about the nature of your own mind. 🧪