Georg Bernhard Bilfinger: The harmony between human soul and body, altogether pre-established, out of the mind of illustrious Leibniz, hypothetically studied (1723)

It is no wonder if you don't remember Bilfinger, because the first work I read from him was short, immemorable and not very original. Although Bilfinger won't get any points for originality this time either, at least the topic is of a more general interest. Like the name says, De harmonia animi et corporis humani, maxime praestabilita, ex mente illustris Leibnitii, commentatio hypothetica aims to examine the theory of the pre-established harmony. Leibniz himself had spoke of harmony between all substances whatsoever, but Bilfinger here concentrates on the particular case of souls and bodies. Bilfinger follows here the example of Wolff, who had already had some reservations on the full Leibnizian theory of monads.

Bilfinger starts from ths established fact that bodies and souls do work in harmony. When an object is brought in front of my eyes, I experience usually a visual sensation corresponding to the object. Similarly, when I have a volition of moving my hand, the hand in fact moves. Thus, the causal series governing bodies and causal series governing souls reflect themselves partially.

Bilfinger considers quickly the possibility that at least one of the series would consist of necessary processes. For instance, Spinoza thought that the series of both bodily and mental events followed necessarily from the eternal essence of God. Bilfinger disregards this option, because the two series do not seem necessary – I could have walked somewhere else etc.

Bilfinger suggests there are only three possible ways to explain the harmony between the two contingent series. Firstly, there could be true causal influx between the two series – this is the common sense explanation. As Bilfinger notes, the influx theory goes against certain assumption of modern science. Observations appear to show that material objects retain the quantity of their motion, unless they interact with other material objects – they either share some of their quantity of motion with others or receive some quantity from others. Because soul doesn't move, it cannot impart motion to material objects, not even to its own body, and cannot thus make the body do anything.

Descartes' stance on the issue was ambiguous. He did accept the physical fact of the stable quantity of motion, but suggested that the soul might still change the direction of movement of the body or some part of it. By the time of Leibniz, it had become evident that this solution would not do – material objects retained also the direction of their motion, unless the direction was changed by the force of other material objects.

The Cartesian school had then slowly turned towards a new explanation. They suggested that whenever body appeared to do something to soul or vice versa, God on this occasion decided to interfere in the causal chain and connect the movement of the body with the respective change in the soul and the change in soul with the respective movement of body. This occasionalism had the setback that it appeared to break the ideas of modern science even more than causal influx. If occasionalism were right, there would be no true causal regularities, but everything would depend on the will of God, who would be constantly making miracles to sustain his creation.

Leibnizian solution is then that God has preordained souls and bodies to work in harmony, like two clocks that a perfect watchmaker has winded up show always the same time. Bilfinger notes that the thesis of pre-established harmony has justification enough in the fact that all other options fail to meet the standards of modern science. Still, he also notes that the harmony becomes an immediate corollary if we just accept other aspects of Leibnizian metaphysics – if souls are monads representing everything and especially the group of monads that constitutes its body, then the representing soul and represented body necessarily work in harmony.

All the previous is pretty straightforward summarising of Leibniz's thoughts. More original are Bilfinger's attempts to answer objections presented against the theory. A good representative of those objections come from Pierre Bayle, the skeptical encyclopedist. Bayle had accused Leibniz that his theory leads to materialism, because he must assume that bodies can run their own course, without any guidance of souls – my body could be writing these apparently reasonable words without me being aware of it. Bilfinger notes that even such complex phenomena like the movement of the planets can happen without any governing soul. Furthermore, he emphasizes that the world still isn't necessary substance of Spinoza, because it has been created by God. Finally, the independence of material world still wouldn't lead to a denial of souls, because mere material things couldn't represent anything – here Bilfinger is following Wolff.

Bayle had also ridiculed the notion of a causal series of the changes of soul. Bayle compared monads with atoms and assumed that monads would also be governed by similar iron laws. Furthermore, he wondered how sudden changes in the experiences of soul could arise, for instance, how could such complex phenomenon like music suddenly appear in our minds. Bilfinger emphasizes the importance of obscure representations in the life of a soul. These obscure sensations make our experiences so varied and thus differentiate monads from simple, featureless atoms. They also help us to understand sudden changes in our mental life. These changes have built up gradually, but only through unaware representations. Only when a certain threshold had been passed will the symphony start to play in our minds.

Even more interesting are Bilfinger's attempt to answer objections he has heard from his own acquaintances. For instance, Bilfinger has to explain why sickness of the body limits also the capacities of soul. Bilfinger notes that this is just natural – because soul is in harmony with the body, the soul sure must follow what the body does and act confused, when the body is ailing. Furthermore, Bilfinger explains that the sequence of ideas in soul must correspond to some movements in brain, which are capable of producing movements of body that appear rational. In effect, theory of pre-established harmony could be reconciled with the idea of human actions being dependent on brain.

So much for pre-established harmony. Next time we'll begin a summary of Wolffian philosophy.

Daniel Strähler: Test of the reasonable thoughts of Mr. Court-Councillor Wolff concerning God, world and soul of men, also all things in general, in which the deductions of Mr. Author are examined, their incorrectness shown, their errors brought to daylight, and both the metaphysical and the connected moral truths set in better light (1722) and Ludwig Philipp Thümmig: An impartial sentiment of a lover of worldy wisdom concerning D. Strähler's Test of the reasonable thoughts of Mr. Court-Councillor Wolff concerning God, world and soul of men (1723)

Philosophical disputes tend to be dirty. You are allowed to misunderstand your opponent and in ambiguous cases always choose the most ridiculous way to read the text. In fact, you can just make a simple straw man as your punching bag and pretend it is your opponent. Because your opponent is allowed to act in an identical manner, philosophical disputes rarely have any winners – or more precisely, they have two winners, at least if we listen to the disputants.

These unwritten rules of philosophical dispute are well exemplified by Daniel Strähler's criticism of Wolff's German metaphysics, Prüfung der vernünftigen Gedancken des Herrn Hoff-Rath Wolffes von Gott, der Welt, und der Seele des Menschen, auch allen Dingen überhaupt, des Herrn Autoris Schlüsse examiniret, die Unrichtigkeiten derselben gezeiget, dessen Irrthümer an den Tag geleget und die Metaphysische ingleichen die damit verknüpfte moralischen Wahrheiten in grösseres Licht gesezet werden and Ludwig Thümmig's criticism of Strähler's criticism, Eines Liebhabers der Weltweissheit unpartheyisches Sentiment von M. Daniel Strählers Prüfung der Gedancken des Herrn Hoff-Rath Wolffens von Gott, der welt und der Seeles des Menschen. As you can see, the gentlemen hardly required any abstracts, when even their titles were a mouthful.

Work of Thümmig we have already met, but Strähler is a new acquaintance. Actually this will probably be the last time when we'll hear of him, as he was more of a mathematician than a philosopher, although he did comment on the fashionable topic of Wolffian philosophy also after this text. In fact, the text in hand deals only with the ontological parts of German metaphysics, while the further parts of Wolff's book were covered in a later publication.

As if sometimes the case in philosophy, none of the disputants disagree about the correct results – Wolff, Strähler and Thümmig all appear to hold e.g. that God exists and has created the souls and the material world, with which the soul is in some sort of contact. Instead, it is the justification of these positions on which the disputes arise.

Many issues that Strähler points out in his criticism concern the definitions used by Wolff. For instance, Strähler notices that Wolff's definition of space as the order of simultaneously existing things is far from satisfactory. For instance, Strähler notes, if I have a shelf full of disordered books, the books will still take space, and in fact, even more space than if they were well ordered.

Strähler's criticism hinges, of course, on the question of what do we mean by order, as Thümmig also notes – it is not the common sense meaning used in sentences like ”he kept the house in good order” that is meant, but a more abstract idea whereby e.g. numbers are ordered according to their size. Investigators of physics, such as Leibniz and Huygens, had defined order in a precise mathematical manner, which enabled them to discuss space in terms of relations between material objects. Thümmig even suggests that Strähler is not much of a mathematician, when he cannot follow such methodology.

If Strähler's criticism is often just nitpicking, Thümmig's countercriticism is usually no better. Thus, Thümmig recurrently notes that Strähler's own preferred definitions are nothing but definitions, because they merely repeat what should be defined in synonymous terms – for instance, changeable is something that can changed but this does not really define anything.

Sometimes such nitpicking does point out crucial errors. For instance, when Strähler criticises Wolff for justifying the principle of sufficient reason by deriving an erroneous proposition from its negation, because one could as well derive true proposions from the same negation, Thümmig is quite right to point out that Strähler has confused a valid and an invalid argument form – that is, while from ”not-p → q” and ”not-q” it is valid to derive ”p”, we cannot use ”not-p → r” and ”r” to derive ”not-p”.

On the other hand, when Strähler notes that Wolff fails to distinguish between real and ideal division of things, he appears to note the very fault I have already commented in the Wolffian theory of substances – i.e. that things might well be potentially divisible into an infinite number of potential parts and still actually undivided and simple, just like in Aristotelian physics. Thümmig fails to comprehend Strähler's point here, because he confuses Strähler's distinction with the related distinction of merely thought and concrete division. Thus, Thümmig identifies Strähler's ideal division with the case of an actually indivisible thing that could be divided in thought – a classic physical atom that still takes up space.

At other times, the disputes seem like mere quibbles of words, for instance, when Strähler accuses Wolff of not distinguishing between ideal or mathematical and real or physical space and Thümmig retorts by noting that Wolff is doing ontology and thus naturally is interested only of the real space. A similar dispute over words occurs when Strähler remarks how the Wolffian definition of substance covers only finite substances and thus assumes either the non-existence or finity of God, and Thümmig answers by insisting that this is only a question of presentation – at this point of Wolff's discourse we are aware only of finite substances, so we might as well leave them out of the definition of substance – and furthermore, emphasises the complete disparity between finite and infinite things – Thümmig even thinks that Strähler himself finitises God by placing him in the same class with finite entities.

In such questions it seems obvious that both Strähler and Thümmig have begun from a presupposition that the target of their criticism is wrong – and then they have just tried to find any evidence for this presupposition. Strähler has assumed that Wolff must be an atheist or at least a bungler, while Thümmig has been convinced of Wolff's ingenuity and thus of Strähler's idiocy, and these preconceptions have coloured their reading.

From a more neutral viewpoint one clearly sees that such preconceptions are often obstacles for true dialogue. Strähler could have admitted that at least Wolff's intensions were not atheistic, and if Wolff's arguments appear not to support such conclusions, then perhaps Strähler had misunderstood Wolff's definitions. Similarly, Thümmig could have noted that Strähler had been right at least in noting a possible way to misunderstand Wolff – that is, in noting insufficiencies and ambiguities in Wolff's theory.

Next time we'll continue with philosophical disputes, and this time we are particularly interested of the question of pre-established harmony.