PARADOXES ABOUT TIME

 

This division of time into past present and future as neat and tidy as our date books, make it out to be Aristotle formulated one of the basic paradoxes of time: time whether limitless or any given length is made up of they’re no longer and not yet.

How can we conceive of that which is composed of non-existence?

Aristotle when he treats time in the physics starts with a riddle that he never answers that goes something like this: think about time as divided into the past the present and the future.

And then think for a while about what the present is how thick is the present?

The present is just a limit between the past and the future then you get the paradox because the past is something that does not exist, it has existed but it does not exist any longer.

The future is something that does not exist, it will exist.

But it doesn’t exist and the present is nothing so time seemed to be nothing dividing something non-existent from something non-existent.

McTaggart considered the ideas of past present and future and wrote a pivotal essay called the unreality of time.

McTaggart points out that however unnatural it may feel to assert that time is unreal, many thinkers have treated it as such and he thought they were right.

Past present and future are incompatible determinations, every event must be one or the other. But no event can be more than one and it is because the distinctions of the past, present and

Future, seem to me to be essential for time that I regard time as unreal.

Mac’s argument is that these notions are in some sense self contradictory and perhaps the easiest thing easiest way to think about that is to think about the present, there’s only one present this

moment is the only present moment, on the other hand every moment is present.

This how do we reconcile these things what is unique about the present moment being

present and now past does the present enjoy some sort of privileged status in terms of its reality or is temple becoming just a subjective illusion of human consciousness for persons.

In 2000 BC that time is real and present for persons in 2050 that time is real and present for them for us our time now is real and present is this just a subjective illusion or is there in fact some sort of privileged status, privileged reality that the present possesses which the past and future do not.

As Kant argues time and space are properties of our mind and doesn’t exist in reality. He calls space the ”outer” sense, and time is the way in which the mind percieves it self. I will just leave it here. But it deeply reasonates with me, as I as well used to be unaware of these ideas.

Hey peoples! The following is an argument which I don’t believe I have ever heard discussed (although I’m sure someone has probably discussed this somewhere and I’ve just never come across it). Basically the argument is that presentism rules out change because it is committed to instantaneous change and instantaneous change is impossible.

I’m not going to explain in very much detail what presentism is, I’m mostly just going to assume some prior familiarity with the view and how it differs from the others. But to put it in very brief terms, presentism is the view that only what is present exists or is real.

That is, the past doesn’t exist (it did but no longer does) and the future also doesn’t exist (it will but doesn’t yet). This view seems to be quite in line with our common sense understanding of time. However, the view has serious difficulties. For example, presentism seems to be incompatible with special relativity.

For another thing, there are deep issues about how we can speak truly about the past and future if they don’t exist (there’s nothing ‘out there’ for such talk to refer to or be about. It seems to require that truths about the past or future can only be about the present, which leads to various problems).

But those aren’t my concerns here. I mainly want to consider the issue of how there can be change on such a view. First, we have to understand why the present must be instantaneous, that is, why it can’t have any temporal ‘thickness’ or temporal extension.

Of course, we often talk about the present in ordinary life as if it was something with considerable duration and extension.

However, the present cannot actually be extended in time. For that would entail that the present would be non-simultaneous with itself, that the present would be non-present.

After all, if the present were of t extension, then insofar as t can be divided, it would be composed of parts that weren’t present. It would have earlier and later parts, past parts and future parts that are not present. So the present must be instantaneous and without any temporal extension or duration or ‘thickness’.

Now, given that any change which happens must occur within the present, since, given presentism, only the present exists and is real, it follows that change can only exist if it’s instantaneous.

That is, presentism entails that change can only be instantaneous. However, do we not have good reasons for believing that instantaneous change is impossible? I believe we do. But if so, then we would have very good reasons for believing presentism is false. For consider something which undergoes some change.

Let’s suppose it changes from some state S1 to another state S2 (i.e. a state that is not-S1). If there’s an instant within which this change takes place, then within this instant of change, the object must be in one of the following four possible states:

(a) In state S1 only.

(b) In state S2 only.

(c) Neither in S1 nor S2.

(d) Both in S1 and S2.

If we answer with (a), then we’re not referring to the instant of change, but we are instead talking about some time immediately prior to the change.

If we answer with (b), then we’re not referring to the instant of change, but instead we’re talking about some time immediately after the change.

And if we answer with either (c) or (d), then we end up in contradiction since, given De Morgan’s law, (c) entails (d) because ~(p or ~p) is logically equivalent to (p & ~p).

And (d) is of course a contradiction.

Ergo, there cannot be instantaneous change.

Now, since the presentist is committed to only the present being real or existing, and since the present is instantaneous, it follows that there cannot be change given presentism unless it’s instantaneous. But alas, there cannot be instantaneous change. Therefore, presentism must be false! I’m interested in people’s thoughts on this.

By the way, there’s an interesting article by Sydney Shoemaker called ‘Time Without Change’. There he gives a famous thought experiment which seemingly shows that it’s possible to conceive of time without change. It’s a fascinating thought experiment and everyone should look into it. But just to be clear, he is arguing for the possibility or conceivability of time without change, NOT change without time. Those are two very different things which shouldn’t be conflated.