Philosophy
The Epistemology of Animal Cognition and the Problem of Other Minds
Quick fact
Philosophers have long argued that we can never directly observe another creature's mind; our knowledge of animal consciousness rests on inference from behavior, and even brain scans are only indirect evidence. This challenge—known as the problem of other minds—applies to other humans too, but becomes especially acute for animals that cannot talk.
Why this is interesting
You watch a dog wag its tail when you reach for a leash. But can you really know that the dog is happy—or are you just assuming it has a mind like yours?