Causal theories of the mind can't account for abstract thoughts? Or for thoughts of things that don't exist? Abstract thoughts don't exist....and you cannot think of anything that doesn't exist.

Sure I can, you will say. I can think of Santa Claus and unicorns, and those things don't exist.

You can think of red, and beards, and old men (all of which exist) and you can think of a combination of those things. Similarly, you can think of horns, the color purple, horses, and fluffy tails (all of which exist) and a unicornable combination of those.

I can think of heaven, and the number 3, you will say. Those are abstract thoughts and they don't exist.

When you think of heaven, what is it exactly that you think of? Clouds? Angels? Green hills? Waterfalls? Our pictoral notion of angels is a combination of things that exist, the rest of these things clearly exist. When you think of the number 3, it is either a visual three or an auditory three, (If you deny this you are deceiving yourself, be honest) both of which exist.

Here's a thought experiment: Try to think of a color that doesn't exist.

Conclusion: There are no such things as abstract thoughts, only thoughts of things that do exist on an increasing scale of complexity. Please comment if you feel so inclined.

Steph Curry on Conan O'Brien tonight.