Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Philosophy

The Trolley Problem and Its Variants

Quick fact

Most people say yes to pulling the lever but no to pushing the man, even though both actions save five lives at the cost of one—revealing a deep puzzle about moral intuition.

Why this is interesting

Imagine a runaway trolley is about to kill five people. You can pull a lever to divert it onto a side track, but that path has one person on it. Would you pull the lever? Now imagine you could push a fat man off a bridge to stop the trolley—would you do that instead?