E se o mundo foi criado a cinco minutos atrás, exatamente como ele era, de fato, a cinco minutos atrás? Estariamos agora “lembrando” tudo o que lembramos agora, porém, todas as nossas memórias seriam falsas. Seria essa hipótese cética sobre a memória uma hipótese válida?
Bertrand Russell, em “The Analysis of Mind“, faz a seguinte afirmação (grifo meu):
“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.”
Para Russell, não é uma necessidade lógica para a existência da crença que recordo agora a existência do evento que é lembrado. E por isso, não é uma impossibilidade lógica a hipótese de que o mundo foi criado a cinco minutos atrás.
Bernercker, em “The Metaphysics of Memory“, apresenta algumas respostas à essa hipótese cética e afirma que essa hipótese é válida e faz sentido. Porém, nessa postagem, apresentarei apenas o que Bernecker expõe como os argumentos que procuram dissolver a hipótese. O que se segue abaixo é baseado na exposição de Bernecker.
Uma das respostas apresentadas é a de que essa hipótese é simplesmente absurda, ou seja, não faz sentido, e por isso, não é uma possibilidade lógica. Essa hipótese não pode nem ser verificada nem falsificada, e isso a torna sem sentido.
Marcus Singer diz o seguinte, fazendo coro a Malcolm:
“[I]ts impossible do conceive of anything that might possibly serve as evidence for an answer that would not itself come within the termos of the question [How do you know that the world did not come into existence five minutes ago?]. Thus for anything selected as evidence for an answer to this question, the very same question demands evidence that this is evidence, and then, of course one would have to supply evidence for this further evidence, and so on. This is why any proposed answer to this question of Russell’s would be question-begging, and this is why it is logically impossible for the question to be answered” (1963, p.190)
Wittgenstein, no “Lectures on Philosophy (1932-33)”, diz o seguinte:
“By examining Russell’s hypothesis that the world was created five minutes ago I shall try to explain what i mean in saying that it is meaningless. Russell’s hypothesus was so arranged that nothing could bear it out or refute it. Whatever our experience might be, it would be in agreement with it. The point of saying that something has happened derives from there being a criterion for its truth. To lay down the evidence for what happened five minutes ago is like laying down rules for making measurements”
Malcolm também afirma que outro fato que torna essa hipótese absurda é que ela simplesmente destroi a possibilidade de termos conhecimento, qualquer que seja, ou mesmo, de termos uma linguagem. Ele diz o seguinte em “Knowledge and Certainty“:
“The five-minutes hypothesis is incompatible with the very concept of evidence. Consider what would be implied by our “believing” that the earth and mankind have just come into existence. If one of us were to “believe” this he would have to renounce not only his previous conception of his own identity, but his entire store of common knowledge – his knowledge of natural processes; his knowledge of the normal properties of anything, so that he would no longer know what wood, water, and fire are; his knowledge of how the words of his language are used or even that he has a language; of how people live, act, and react; of what interests them and what kinds of inquiries they make; of how measurements, experiments and arguments are conducted, and when something is held to be proved…. If he thought out consequences of this hypothesis he would realize that it is not anything he could rationally believe, because “believing” it would mean that he no longer understood anything at all… To accept this “hypothesis” as true would mean the destruction of all our thinking”
Essa afirmação de Malcolm reflete o que Wittgenstein diz no “On Certainty“:
“If you are not certain of any fact, you cannot be certain of the meanings of your words either. If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty” (§114, §115)
Para esses autores, a hipótese cética de que o mundo foi criado a cinco minutos atrás não faz sentido, é ininteligível, e por isso, é uma impossibilidade lógica, dissolvendo assim o problema levantado pelo cético.