Newton’s claim of the existence of Absolute space was attacked by the relationist Leibniz in a correspondence with the absolutist Clarke. Leibniz appealed to the maxim that nothing happens to be one way without a reason for it being such, and said that through looking at absolute space from this angle, it would be shown to be untrue.
Here, Leibniz’s choice of the word ‘reason’ might be somewhat misleading, so it is best to understand this as the principle of sufficient ‘cause’, in that everything must have a sufficient cause.
Here, Leibniz says that if there were this absolute, homogenous space, there would be no reason, or no cause, for God to have created the world where it is in relation to absolute space as opposed to somewhere else (ironically, it is Clarke who first mentioned the different universes, which were then turned against him). There could be no rational explanation for the universe to be where it was, thus implying that God had acted irrationally.
Clarke then counters this point by pointing out that the cause for the universe being where it is can be explained by Gods will. All that was requisite for the universe to be where it is is that God willed it to be in such a place. To say God could not make such a decision is derogatory to his free will. This is similar to the story in Godwin’s book ‘Free Fall’ in which the main character feels truly alive when he is confronted with three different paths to take to a field, as there is no reason for why he would choose one path over another; thus he is totally free to do as he pleases without any external influences.
Leibniz counters this by pointing out a more psychological point, asking what would make God pick one location rather than another. There must be some cause behind God’s choice. This point is a pre-emption of behavioural psychology, where one can look for cognitive, sub-conscious reasons for ones acting in one way rather than another. Clarke says that no further reason other than God’s will is needed, but this reply seems inadequate. Clarke has already agreed with Leibniz that PSR does hold, but then seems to rule this out when it comes to God’s willing. By saying that God acts without some reason implies that his action was random, but developments in psychology don’t seem to align with this way of thinking. If I were given a piece of paper, and asked to draw a circle anywhere on it, and decided, for no reason known to myself, to draw one in the top left corner, the psychologist claims, based on scientific methodology, that there are reasons for why I chose this part of the paper, even though I am unaware of these reasons.
Leibniz’s alternative to absolute space- Relationism- does no seem to fall victim to this problem. Without absolute space, the ‘placing’ of the universe is nonsensical, because there is nothing to place the universe in. The universe just is the interrelation, and relations between the material objects present. One could ask, why did God place these objects in such relations as they are, but this can be overcome by pointing out that even if God had just thrown these objects, so to speak, then they could have come to the relations they have now merely by physical forces acting upon the different masses, causing the repelling and attraction of some to others.
Then again, we could take another step back and ask, what is the sufficient reason for these physical forces? But this question can be asked to both the relationist and absolutist for these laws hold true in both cases and so answering this question does not seem to have any bearing on the existence of non-existence of absolute space. These questions seem more suited to the physicist.
These arguments seem to rest heavily on different conceptions of God, which neither Leibniz nor Clarke properly argue for. Leibniz assumes God’s willing has the same basis as our willing, Clarke assumes that God’s willing is not subject to PSR. Besides this important point, it does seem that Leibniz’s view is more compelling as it relies less on abstract conceptions of the imagination. His Descartian rationalist approach seems to demand less of the world than the alternative absolutist view.
What can be said from this argument however is that thus far, the world can be explained without reference to absolute space. As soon as Newtonian Absolute space is posited, we are left with more questions than we started with. What is this space? Is it a substance or property? Where did it come from? How can it have an effect on material things?
The idea that the universe exists in absolute space alone shines no light whatsoever on our understanding of the world. There seems to be no basis for positing such a thing other than attempting to explain the common preconception of an infinite amount of empty pace in the universe, which, when thought about in more detail, as Leibniz, and Mach did, really clears up nothing. Even the difficult problem of inertial effects can be explained in relational terms, so there seems to be no reason to conjure up this absolute space. That is not to say it does not exist, just that with appeal to Ockham’s Razor, it seems nonsensical to hold absolutism over Relationism due to its much higher demand for explanation, and the multiple questions it raises of itself, so in this light, Relationism does seem to come out on top.
(Note, PSR doesn’t seem to pre-suppose any intelligent creator, another positive for Leibniz: ch8, Space and time)
