McTaggart’s argument against the existence of time
McTaggart is famous for arguing that time doesn’t exist, but is merely an illusion. While I believe that McTaggart’s main argument is heavily flawed, there is an important insight that is buried deep within there.
McTaggart described both an A-series and a B-series model of time (he also describes a C-series, but that isn’t important here). In the B-series, the concept of the present isn’t considered to be very meaningful. We can say that I am writing this blog post 3 months after the start of the year, but a B-theorist might be critical of the sentence “I am writing it now”. They would argue that it doesn’t have any meaning deeper than, “at the time this statement was made, I was writing”. In contrast, the A-theorist believes in the intuitive idea that “now” means more than this, that now is a coherent and meaningful concept.
McTaggart’s argument consists of two parts. We’ll actually start with part two, since part one isn’t actually a very good argument. After McTaggart disproves the viability of the A-series (at least in his mind), he argues that the B-series wouldn’t give us a real, substantive, notion of time. He argues the essence of time is change and the B-series is rather static without a concept of now. I think he is right in that the B-series by itself leaves an unanswered question — how does an event move from being in the past, to being in the present to being in the future within a static model like the B-series. I see two viable approaches to resolve this — either explain why all our intuitions of time passing are incorrect or to add something to the B-series model that explains this phenomena. I won’t dive any deeper into this at the moment, since I’m not sure of the best answer myself yet.
With this is mind, it is easier to understand part one of his argument. McTaggart is trying to understand how an event can move from being in the future, to the present and then to the past. He notes that if we (stupidly) try to model this by assigning the past, present and future properties all to a particular time, the result is non-nonsensical.
The obvious counter argument is that a time doesn’t have all these properties at once, as time changes an object can move from being in the past in the past, to being in past in the present, to being in the past in the future. This expands his three properties to nine — past-past, past-present, past-future, present-past, present-present, present-future, future-past, future-present, future-future. He that have defined nine properties instead of three still doesn’t allow him to assign them all to an object, neither does defining 27, 81 or more.
Now, this seems like a pretty huge straw-man. I don’t believe any significant A-theorists would argue that past, present and future are all properties possessed (timelessly) by a single time. Nor would they embrace McTaggart’s flawed attempt at fixing the problem. Perhaps they argue for a meta-time, or that the concept of “now” is a primitive that cannot be further broken down or something else. This is what should be debated — not these weak models of real temporal change.
McTaggart believes that he has made a challenge to the A-series model and that attempts to fix it only create new problem until infinity. That’s not quite what happens. McTaggart says “you can’t simultaneously be past, present and future” and the A-theorist says, “I never claimed that, only that you were future, are present and will be past”. McTaggart then says “you can’t simultaneously be past-past, past-present, past-future…” and the A-theorist makes a similar correction that that wasn’t what he said. It isn’t that McTaggart has asked a single question and that the A-theorist has to adapt his model, instead McTaggart is asking a series of questions based on misunderstanding the A-theorist model and the A-theorist is correcting him by pointing out that he never claimed that. This says nothing about the A-theorist, but plenty about McTaggart.
