1/10. Space and Time in Leibniz and Newton (1)

Transcription

1 1/10 Space and Time in Leibniz and Newton (1) Leibniz enters into a correspondence with Samuel Clarke in 1715 and 1716, a correspondence that Clarke subsequently published in The correspondence was prompted by a letter Leibniz wrote to the Princess of Wales suggesting a problem with the relationship of Newton s thinking to the understanding of natural religion, religion, that is, that is grounded on philosophical argument concerning nature. Whilst we will attend to the element of this correspondence that concerns natural religion as it is connected to the other questions of the correspondence between Leibniz and Clarke, the main area that we will be exploring will be the relationship between metaphysical principles and the understanding of space and time. The different views expressed by Leibniz and Clarke of the status of space and time are intimately related to views concerning natural religion for reasons we will see but keep always in mind when thinking about this the metaphysical principles that are at issue in these arguments. In his original letter to Princess Caroline Leibniz accuses Newton of having a very odd opinion of the work of God and want he describes as odd is that it seems that, on Newton s view, God needs to intervene in the universe in order to keep it working. In contrast to the view, that there needs to be some intervention by God in the working of the universe, Leibniz points to his own view that there is always maintained in the world the same quantity of force which only passes from one part of matter to another. In

2 2/10 this first letter Leibniz also questions what Newton can mean in suggesting that space is an organ that God makes use of to perceive things by. In his first reply Clarke denies that Newton views space as an organ to view things by and denies that God would need any medium at all to perceive things with. Since Clarke takes God to be omnipresent then he perceives things by immediate presence in all space wherever they are without need of any organ. However Clarke does have to interpret Newton s view here and indicates that Newton was speaking in terms of a simile when he referred to space as the sense of God. Having apparently dealt with this point Clarke moves on to the question as to why it appears, on Newton s view, to be the case that God needs to intervene in the universe to keep it going. The reason he gives is that when human beings create something then what they do is take matter that is already to hand and adjust it in certain ways without directly creating the forces that are at work in such things as weights and springs. In the case of God, by contrast, things are quite different since God does not just put things together but creates and preserves the forces and powers themselves. Since God conserves the forces and powers it is not surprising that he needs to act to keep them moving as if he did not we would only have a blind fatalistic mechanism. Effectively in making this point Clarke suggests that Leibniz is the one who is undermining natural religion, as it is the effect of Leibniz s doctrine to exclude God from the world.

3 3/10 Leibniz s second paper presses the point that the defenders of Newton are little different from materialists and indicates points of agreement between Newton and Hobbes to show this. In arguing in this way he wants to suggest that whilst Clarke presents the defenders of Newton as representatives of a mathematical view of nature that, in fact, they are defending a metaphysical one. In making this point Leibniz argues that the foundation of mathematics is the principle of contradiction, a principle that he conflates with the principle of identity but which he argues is the foundation of arithmetic and geometry. Leibniz then adds the point that to move from mathematics to a philosophy of nature we need another principle in addition to this, namely, the principle of sufficient reason. This principle is the key metaphysical principle that Leibniz now uses in his attack on Newtonianism. The principle basically states that nothing happens without a reason why it is the case. This principle is one that Leibniz thinks is connected very clearly to a correct understanding of the principles of dynamics, that is, to the view of force. Leibniz s difficulty with the Newtonian position is now turned on a point that is particularly important, namely, the relationship between space and the matter that is in it. Matter is taken by the Newtonians to only fill a certain part of space so that they believe there is such a thing as empty space. Leibniz indicates, by contrast, that the more matter there is in the world the more there will be an account that can show how well-governed the world really is. The Newtonian view of space as a sensory element of

4 4/10 God requires furthermore, says Leibniz, that there is more than just the presence of space. It also requires some communication between matter and space, an influence of one on the other. For space to be as Newton says it is requires that there be left in it some trace of the influence of body upon it and of it upon body. On Leibniz s own view, the reason why God perceives things is not simply due to presence but to action, action that is involved in production of the perfection of things. The nature of this cannot be accounted for however by Clarke s distinction of the way a workman operates on things by comparison with how God does. If it were merely that God creates what works, not merely rearranges it as a workman does, then it would follow that God was greater than workmen only in power whilst Leibniz alleges the real difference between them concerns wisdom. In saying this, Leibniz responds to the argument Clarke made that on Leibniz s principles there is nothing really for God to do in the universe. In reply, Leibniz points out that the way God works in the world on his conception is in terms of preestablished harmony and that this harmony shows real wisdom in God. Finally, Leibniz returns to the question of what would be involved in God having to intervene in the universe to keep it moving, pointing out that either this means that God has to act naturally or supernaturally. If he has to act supernaturally then this makes the laws of nature depend on miracles which would be absurd as that way we can always explain everything without having to enquire into anything. But, if God is instead required to

5 5/10 act naturally, then he is no longer beyond the world but merely immanent to it which collapses into the position of Spinoza. Clarke s second reply to Leibniz admits the point that the Newtonian position is a metaphysical one as it has metaphysical consequences and he concedes the principle of sufficient reason to Leibniz but then immediately limits its scope saying that the reason why many things are the way they are may simply be because that is how God wills it. An example of the reason for something being only the will of God that is given is that why one particular piece of matter is in one place rather than another when place is essentially indifferent to all matter. Clarke s point here is that surely it is indifferent why two pieces of matter that are otherwise alike should be in the particular places they are as nothing fundamentally would alter if they were in different places. Clarke also denies that the question of how much matter there is in the world should have any consequences for how we view the government of the world since however great or small it is there would still be the same ability of God to exercise power and wisdom. Clarke s next main point is to return to the question of whether he has said that the presence of space was sufficient for God s action which he denies now that he was earlier asserting adding only that he was saying that it was necessary for this action. For action to take place requires presence and God does indeed perceive things not just by his presence but also by his operation. Similarly, Clarke concedes that we have to account not just for God s power but also for his wisdom but states that this wisdom is shown to

6 6/10 us in the perfect and complete work that the universe represents by means of God s uninterrupted exercise of power. In accounting for the need for God to intervene in the world Clarke points to the fact that the present solar system will, due to the pressure of entropy, decay. It is due to this tendency towards entropy that a reformation of the universe will subsequently be necessary to restore order, a restoration that requires God s action. This is the sense Clarke gives to the conservation of things by means of God, namely that powers and motions are repaired and continued whilst he still presses the point that the involvement of God in the universe on Leibniz s conception is not real. However in concluding this defence Clarke also suggests that the distinction between natural and supernatural action is one that does not really describe the true nature of things but is only a distinction of our reason. The basis of this claim is that whether God causes the sun to move or not is an effect of no greater power on his part so that whatever it is that he does involves the same kind of action on his part and it is only our reason that frames it differently. In opening his third paper Leibniz articulates the distinction between mathematics and metaphysics pointing out that whilst the former concerns numbers and figures, the latter involves notions such as cause and effect. Having made this point Leibniz returns to the principle of sufficient reason, a principle Clarke admitted. However Leibniz suggests that Clarke has not fully understood the principle that he admitted. In arguing this he now gets to the heart of his dispute with the Newtonians. Newton claims that space is

7 7/10 a real absolute being which, says Leibniz, would have to be eternal and infinite and much like God himself. However, since space consists of parts, it cannot be like God or be a part of him. In contrast to the view that space is a real absolute being Leibniz contends that it is only an order of coexistences as time is an order of successions. Space involves a possible order of things existing simultaneously. In replying to the view that space is absolutely real Leibniz suggests firstly that this involves viewing space as a substance but goes on to give an argument for saying that if we view space this way we will be forced to admit that some things happen without a reason. The argument is that since all the parts of space are homogeneous it follows that no point of space differs from any other. On this basis it would seem that there is no reason why one thing should be in any given part of this absolutely real thing rather than in any other part. So any given thing could be pointing east rather than west. On Leibniz s view, by contrast, space is nothing else than the order or relation bodies have to each other and without bodies it would be nothing else than the possibility of bodies having certain relations to each other. The difference between two states which cannot be explained on the basis of absolute space can clearly be explained on this conception as merely a difference of relation. Leibniz then gives a parallel argument with regard to time asking why the universe was created at one time rather than another. If time is something absolutely real then we require an answer to this question but

8 8/10 cannot receive it. If instead we view the parts of time, the moments of it, as only part of successive ordering of things, then there is no problem here that requires an answer. Leibniz also picks up on Clarke s conception that reference to the will of God alone would be sufficient reason why something is one way rather than another. This clearly gives no reason at all however so is not an example of things being governed by the principle of sufficient reason. Leibniz replies to Clarke s argument concerning entropy by stating that if disorder mounts in the way suggested by the hypothesis of entropy then it follows that disorder is part of the essence of nature which detracts from the view that God works always for the best. So the argument concerning the need for intervention is here revealed to be one concerning the order of the universe itself. Finally Leibniz responds to the question of the relationship between natural and supernatural pointing out that the supernatural must be something that exceeds all power of creatures and requires miracles. Leibniz also suggests that Newtonian attraction is an example of something that would be a miracle. Clarke s third reply begins by looking again at the principle of sufficient reason and indicating why he thought he could limit its scope arguing that some things are in their nature indifferent. Clarke also argues that some things would be indifferent whether space were absolute or not and that Leibniz s arguments have not shown otherwise. Different spaces are different from each other despite being homogeneous. Clarke also

9 9/10 argues against Leibniz s relationist view of space saying that on Leibniz s conception it follows that if the place of the solar system and the stars were reversed it would follow not just that there was no difference in effect but that each would really remain in the same place despite having moved which is a contradiction. Clarke suggests next that it is not Newton s argument that space is a real being but that it is a property or consequence of the existence of something that is infinite and eternal. Whilst space is immense, immensity is not itself divine and so space is not. Since space is infinite however it follows that it is essentially indivisible as to divide space is essentially impossible since within the parts divided there would still have to be spaces which supposes space divided and not at the same time. Hence there is in fact only a figurative sense that can be given to the notion that space has parts. It also follows on Leibniz s relationist view of time that if the universe had been created millions of years earlier than it was that it would not in fact have been created any sooner than it was! Clarke subsequently denies that the tendency to entropy involves disorder in the world precisely due to the ability of God s active power to rectify it. Finally in response to the question of miracles Clarke suggests that if a miracle is only something that surpasses the power of created beings then it follows that for a man to walk on water is not a miracle as this would not require infinite power although he also goes on to add that if whatever does not come from natural powers of body was a miracle then it

10 10/10 would follow that motion is a miracle. On these grounds Clarke disputes Leibniz s notion of a miracle.