Stephanie asked:

What would Descartes and Hume say if they looked out a window and saw a red bird?

Answer by Craig Skinner

We can only speculate, but here is my suggestion.

Descartes (I translate into English):

"Mon Dieu! I have a clear and distinct idea of a red bird. God being no deceiver, I can trust my senses, and so take it that there is a substantial (res extensa that is) bird out there. Mind you, senses can deceive, it’s difficult at this distance, maybe it’s a soft toy, and red birds are rare here in Stockholm. There again (Ho Ho!) it might be a dream or hallucination, after all I am in bed with pneumonia and high fever – these freezing-cold early morning sessions teaching Queen Christina are killing me.

"Of course, by the way, when I say it’s red, the redness is entirely in my mind, not in the bird.

"Now it’s rooting around for worms or insects to take back to its young. Of course, it’s not that it cares for the young, or feels anything for that matter. After all, unlike we humans, it has no soul, it’s just a complex machine (like our bodies are too of course), and we needn’t worry what we do to birds or animals, they feel nothing. Actually, I do wonder about that sometimes, but it allows natural philosophers to get on with the science of animals and of the human body without getting in the Church’s hair.

"Ah well, back to re-reading those tiresome objections to my Meditations by those bores Arnauld, Gassendi and company. Dont these people ever see anything clearly and distinctly!"

Hume (beyond the first sentence I wont reproduce his Scottish accent, which Londoners ridiculed):

"Hoots mon, there’s a burrd loose aboot this hoose!

"To be exact, I have an impression of a red bird. Let others speculate as to the ultimate cause of this impression – myself, an external world, God ? – me, I’ll stick with Newton’s ‘I feign no hypothesis’.

"Oh, sorry," [turning to his backgammon opponent] "I thought for a minute I was still in my study instead of back in ordinary life. Yes, it could be a particularly florid redwing. It’s been here at the same time every day recently for the bread my housekeeper scatters. Just shows you. Like us, birds think by association of ideas, and the constant conjunction of the housekeeper’s appearance and the bread on the grass has induced him to expect the latter on observing the former. Eh! How’s that for a theory of causation.

"Look, he takes some bread back for his young. They seem to have a deal of sympathy for kin, and kind, and maybe more widely. Looks like a naturalistic view of ethics might fly as it were (chortling).

"It’s difficult to imagine that that bright redness is all in the mind as Galileo and Descartes have it. Nah, Locke’s on the money with it being a secondary quality in the mind produced by the primary qualities in the object, so, as powers to produce them, colours are in the object.

"And another thing. What good would red plumage be at attracting mates if they didn’t have minds to house an impression of it. Take that one on board Des.

"Anyway, last game, then its upstairs for me, unlock the desk drawer and work on that tome about religion. If my ideas there don’t get too widely known, I could still be in with a shot at the Glasgow Chair despite getting the bird (parting chortle) in Edinburgh."