WRT the discussion, Jane seemed to think that just because something like vision is subjective, that any statement of fact based on seeing something is subjective. But I may not know what you really see when you see red (maybe it looks like blue does to me), but if you blow through a red light in front of the police, that's not going to get you out of a fine.

Even somewhat subjective experiences can lead to statements of replicable facts. If you run a red light, you're breaking the law and might get a ticket. If you see a rocket explode on takeoff, it's gone.

Now, if you're going to argue that everyone sees a completely different reality, well, that's a subject for a Philip Dick novel.