A perennial philosophical poser is whether people see the same colours as each other — and how could we ever know? To some, this introduction to the philosophy of mind is the first time they’ve consciously pondered the concept of external perspectives.
The fundamental acceptance of the existence of external perspectives is the really interesting part to this, beyond merely acknowledging an unknowable. It’s the very conclusion that we can’t possibly test for it that forces us to recognise both that what we separately perceive is somehow constant, and that how we make sense of the external world is a purely internal language.
Before I continue I’ll caveat this with the recognition that this relies on the assumption that the external world and external perspectives exist at all — there are interesting creative implications when we don’t accept those tenets too, but they’re for another time.
Thomas Nagel’s What Is It Like to Be a Bat is a philosophical essay on consciousness that proposes an interesting thought experiment that I’ll butcher and use a small part of to illustrate this point. Bats use echolocation to understand their objective surroundings with staggering accuracy, able to comprehend subtlety of reality much as a human does by sight. So… if it’s getting broadly the same information about objective reality as humans, does a bat’s conscious experience have the same qualities as a human’s? Or to put it another way, is attributing a visually constructed mental experience of the world to our eyesight just bias?
These aren’t (just) after-party-esque cod philosophy ramblings; they bring me to my central point. If we accept that there are objective truths about reality but our perception of those truths is purely subjective, that people may see colours differently in comparison to each other becomes less important. Everything we superficially experience is a metaphor that we create to navigate our consciousness, and all communication is an interface between two completely separate but internally consistent metaphors.
All this to say one thing: assuming there are objective truths about the external world, the best design understands that it is the objective truth that is being recognised. Communication is the transmission of our individual perspectives on that objective truth.