Here is anonymous question from r/AskPhilosophy!
I came across mention of Russell’s “world is five minutes old” hypothesis and it’s been genuinely distressing me. Does he ACTUALLY believe something that outlandish? And if he does not, why he does not?
Russell does not believe that the world is just five minutes old, or that it is equally plausible as the common sense hypothesis that it is as old as our best scientific theories suggest.
Russell’s point in the passage (in full here), which is in The Analysis of Mind, is that an event of remembering occurs in the present. Even the image, thing, or event recalled is the content of our present memory awareness. What is remembered does not exist in the past. So remembering on its own does not prove that what is remembered actually occurred.
Philosophers sometimes fall this feature factivity, and this feature amounts to the ability to always trust whatever capacity is factive. So if I perceive something, I can always trust that I am perceiving something, even if it is a hallucination or dream. Something is still being perceived, even if it is only in my head and so is not real in the usual sense of that word.
Using this notion of factivity, Russell is just saying that memory is not factive. Why? Because it is logically possible that everything we remember as happening years in the past didn’t happen at all: our present remembering is logically consistent with everything we remember being illusory.
This doesn’t make it reasonable to believe that the world is only five minutes old. Logical consistency is a low bar, and the fact that the five-minutes hypothesis meets it does not make it credible. Russell says this in the paragraph immediately after the five-minutes hypothesis passage (page 160):
I am not suggesting that the non-existence of the past should be entertained as a serious hypothesis. Like all sceptical hypotheses, it is logically tenable, but uninteresting. All that I am doing is to use its logical tenability as a help in the analysis of what occurs when we remember.
So Russell does not believe that the world is five minutes old. He is using this hypothesis to show that the logical analysis of memory will not show that what is remembered is accurate, and instead must accommodate that our ability to remember is not factive, a point that only grows more apparent to me as I grow older!