Recently I heard someone object to the idea that we can know anything at all by saying, “How do you know the universe wasn’t created five minutes ago?”
I responded: “What in the world do you mean? Why think that?”
“Well, it could be true, and you can’t prove that it isn’t true.”
Perhaps you have heard someone make a similarly grandiose claim. There are many different kinds of unsupportable, evidence-free assertions that purport to discourage us from thinking we have knowledge of the world (“we are all brains in a vat,” and so forth).
Interestingly, the humanist Bertrand Russell originally proposed The Five Minute Hypothesis. As he put it:
In investigating memory-beliefs, there are certain points which must be borne in mind. In the first place, everything constituting a memory-belief is happening now, not in that past time to which the belief is said to refer. It is not logically necessary to the existence of a memory-belief that the event remembered should have occurred, or even that the past should have existed at all. There is no logical impossibility in the hypothesis that the world sprang into being five minutes ago, exactly as it then was, with a population that “remembered” a wholly unreal past. There is no logically necessary connection between events at different times; therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago. Hence the occurrences which are CALLED knowledge of the past are logically independent of the past; they are wholly analysable into present contents, which might, theoretically, be just what they are even if no past had existed.
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.
In other words, Russell knew that this was not a hypothesis worthy of serious consideration. He brought it up only to clarify a point in his discussion of memory. But despite Russell’s restraint and logical clarity, apparently some people are now taking this idea seriously. And so it is appropriate to consider a thoughtful response.
First, when Christians argue this way, it looks equally absurd.
Imagine: “Christianity COULD be true, and since you can’t PROVE that it is false, why not believe it?”
That’s hardly convincing, right?
To say this is to make a huge assertion – that Christianity could be true.
But then there is an avoidance of any rational support for such an important idea.
Finally, the burden of proof is completely reversed: unless you can disprove my big idea, you should accept it. Wait a second – you came up with the idea, so you have the responsibility to explain why it is persuasive!
This kind of non-argument for Christianity rightly frustrates atheists, agnostics, and people of other religions. (A better approach: offer good reasons for the truth of Christianity).
So the Five Minute Hypothesis involves two critical mistakes: it is 1) a huge assertion without any evidence in its favor and 2) it involves unfairly reversing the burden of proof.
Second, the hypothesis is incapable of ever being proven.
Let’s say you offer some good evidence in favor of the Five Minute Hypothesis. (What kind of evidence, I have no idea!)
Now, presumably, I have to remember that evidence while I think about whether or not it is convincing. Let’s say it takes you a good hour to explain all the evidence to me and about one more hour for me to properly think about what you have said. At this point, two hours have passed since the creation of the world, “with a population that “remembered” a wholly unreal past.”
I would have the experience of two hours of genuine memories – and an apparent memory of a few decades that are entirely false and illusory. On balance, I would now have good reason to doubt that my memory is a very accurate source of knowledge! The vast majority of it is entirely false, though it appears to be real.
Given how unreliable my memory would appear to be, I would have to doubt that I had really heard good evidence for the Five Minute Hypothesis or ever really thought about the evidence seriously. All I have is my unreliable memory to go on!
Furthermore, though I don’t have any idea what kind of evidence could be given, I wonder if it would not be the kind of evidence which would be equally good at proving that the Five Minute Hypothesis is true of a universe that began at 12pm yesterday, or at 12pm a week ago, or at 12pm a year ago.
In other words, once you try to show that our memories are fundamentally flawed and wrong, it becomes quite difficult to remember whether or not you are right about that!
Third, it leads to unrealistic conversations.
If we accept the process of persuading each other here – giving unsupported hypothesis, reversing the burden of proof, doubting all of our memories – then we should be open to other, similar claims. For instance:
- Best I can remember, about two minutes ago, you promised to give me 30% of your net income, payable the 1st of every month. Remember that? I sure do.
- As I recall, just a minute ago you said your life dream was to spend your life pretending to be a statue of Elvis Presley. When do you plan to get started with that?
- If memory serves me well here, it COULD BE TRUE that you have promised to do my laundry every weekend. Since YOU CAN’T DISPROVE that you promised to do so, why not believe it is true?
If your friend is willing to take these silly ideas seriously, then at least he or she is consistent, and you’ll have some extra income and free laundry service. But more likely is that the absurdity of the idea becomes clearer and your friend is willing to move on.
Fourth, if no claim is being made, then the hypothesis becomes irrelevant.
Another way this can be approached is to say:
- “Oh, I’m not saying the world WAS created five minutes ago, just that it COULD have been.”
- “All that The Five Minute Hypothesis shows is that we COULD be wrong about everything.”
- “I’m just asking a question here, not making a point that has to be defended.”
In all of these cases, the attempt is being made to get out of defending an actual point. The next step: ask for a commitment to a particular truth claim. Then ask for reasons to believe the claim is true. If they want to avoid this, then…
Sometimes, you just have to reach disagreement…
In the worst case scenario, your friend might say, “No, I don’t think the world was created five minutes ago, but it could have been, and that would mean our beliefs about the past are false. I don’t know if it is true or false – I don’t even care if it is – because I don’t think we can know anything at all.”
You respond: “But that’s absurd and self-contradictory! You are claiming to know how to use English, what the ‘world’ is, the meaning of the phrase ‘five minutes’, and much more! How can you say you don’t know anything at all?”
They respond: “Because I can. I know it is absurd and I am okay with absurdity.”
Perhaps this sounds like an outlandish conversation, but I have had a number of conversations like this at Harvard.
In this situation, reaching disagreement is the best you can do. “Ok, you affirm absurdity, I seek to be reasonable, at least we know what we both believe.”
Questions for Reflection:
- How would you respond to The Five Minute Hypothesis or a similar scenario?
- How do you keep a conversation going when it reaches the place of self-acknowledged absurdity?