Monday, March 25, 2013

Metaphysics course concludes

I have reached the end of the 3rd course. The final module was on the subject of the reality of space and time. I found the arguments somewhat artificial, and didn't manage to contribute much to the final module due partly to work commitments. My final assessment was submitted on the subject of Plato, I will upload a copy once it has been marked.

I've signed up for Ethics, starting in May. I can't promise to post before then, but will try my best.

Thursday, March 21, 2013

Leibniz and the principle of the identity of indiscernibles

I agree that the Principle of the Identity of Indiscernibles (PII) doesn't seem, initially, to "do any work" in Leibniz's argument. I've been trying to get my head around what L. means and am beginning to understand what he is saying (I think). At first I thought PII was tautologous but on reflection my view has changed.

L. is using PII to argue that two indiscernible things could only be 'separated' by space and time, hence if there were indiscernible things separated by space and time then the properties of space and time become properties of the objects. L. doesn't want this argument to succeed, therefore he argues that there are no indiscernible things, in terms of all of their non space time properties.

I'm not sure I agree that L. doesn't use the Principle of Sufficient Reason. He is arguing that were the universe to be created earlier or in a different place, there would need to be a reason, and there couldn't be such a reason, therefore it couldn't happen? Again, if the universe were to be created in a different space or at a different time then space an time become properties of the objects and therefore have some absolute existence and are not merely relational.

Both arguments certainly stretch the thinking, but I was wrong to rush to judgement.

I do think however, that L.'s philosophy is driven by his Theology. I also agree with him that there probably aren't two indiscernible things (excluding their position in space and time) at the macro level but I'm not sure this achieves what L. wants.

It could be possible that space and time are both absolute and relative. I'm not sure whether it is fair to argue that these two views are mutually exclusive.

Are space and time absolute?

I suspect there may be some confusion (at least on my part!) regarding what we mean when we say space and time are absolute for the Leibniz type philosophical argument and the meaning of absolute used in the Einstein space/time sense. I think we possibly have two different types of absolute / relative distinctions going on.

For Einstein the argument is whether time is "fixed" and this sense of absolute is different. Einstein says no, time is relative to the observer.

For Leibniz the argument is whether time is absolute, i.e. exists independently of events that happen.
I don't think these two meanings of absolute relative are quite the same, but am happy to stand corrected as it is a fairly mind boggling subject!

If time is relative to the speed of light (which I accept) then could we not still say that time is absolute as far as Leibniz debate is concerned? If the speed of light is fixed, then in one sense time is also fixed in relation to the speed of light. Time is therefore the same everywhere, allowing for its relativity to the speed of light. Time is not something which is imposed by the mind, it is a real "thing" and depends on the speed of light and distance (i.e. not on events).

Similarly for space. Space may be able to bend, but it is still and absolute "thing" in one sense, again relative to the speed of light and time.

One interesting question, which I don't profess to know how to answer, would be will space still exist if there is nothing in the universe (i.e. the heat death of the universe). Once entropy has worked its wicked way to total finality, could we still talk about space?