Christian Wolff: Reasonable thoughts on God, world, and human soul, furthermore, of all things in general (1719)

In 1982 appeared a humorous scifi book bearing the lofty title, Life, the universe and everything. Wolff's Vernünfftige Gedancken von Gott, der Welt und der Seele des Menschen, auch allen Dingen überhaupt attempts something similar, just replacing life with soul and adding God as a bonus. But the loftiness is in order, because a new era in German philosophy was about to begin: this is the first ever book on metaphysics in German language.

The words in the title of Wolff's book are not just flowery decoration, but tell quite explicitly what Wolff's book is all about. It investigates, firstly, God. This happens in a discipline that was traditionally called natural theology – that is, based on facts that could be known by a person in a state of nature, while revealed theology relied on Bible and church traditions. Secondly, Wolff's book investigates the physical world or contains a study on cosmology. Thirdly, it investigates human soul, based both on observations of human behaviour (in empirical psychology) and on indubitable reasoning (in rational psychology). Finally, it investigates characteristics shared by all things, that is, ontology. But before any of these discplines can begin, Wolff wants to find an indubitable starting point for his investigation.

In many periods in the philosophy of history, there has been a definitive Philosopher, who one must comment upon, if one is to do serious philosophy – one might not agree in everything with the Philosopher, but even this disagreement must be presented as a commentary on the Philosopher. In the medieval times the Philosopher was Aristotle, in German idealism, Kant, and in certain period of analytical philosophy, Wittgenstein.

In the early 18^th century philosophy the Philosopher appears to be Descartes. We have seen how Lange followed closely in Descartes' footsteps in his description of the natural light of human reason and how Rüdiger took Descartes as one of his main opponents and as the paradigmatic representative of modern physical mechanism. Now we are about to see how Wolff begins philosophy in a Cartesian style.

Indeed, the first paragraphs of Wolff's German metaphysics start from the certainty of the existence of the metaphysical investigator: even if you doubt your own existence, you are at the same time confirming that it is you who is doubting. Even egoists cannot deny this reasoning – egoists being here those who later would be called solipsists, that is, philosophers believing ony in their own existence.

And like Descartes, Wolff uses the discovery of this incontrovertible starting point as an example of the correct methodology. But instead of Descartes' clear and distinct perceptions Wolff inserts his own methodology that we have discussed in earlier texts: our knowledge of our own existence is based on an incontrovertible experience – we are conscious of ourselves and of other things – on an analytical statement – what is conscious, exists – and on rules of syllogistic reasoning.

In fact, it is rather remarkable that according to Wolff, the Cartesian ”I think therefore I am” is a syllogism, when Descartes himself was convinced that it shouldn't be expressed as a syllogism: Cartesian sentence is immediately certain and convincing, while it supposed basis ”all that is conscious exists” is not. The difference reflects the difference in the attitudes of the two philosophers towards syllogistic: Descartes thinking it it an outdated model science and Wolff endorsing it as the true model of science.

Wolff's syllogistic interpretation of Cartesian meditations is interesting also for Kant-scholarship. As we will someday see, Kant expressed the arguments of rational psychology, such as Cartesian cogito, in a syllogistic form. If Kant's criticism would be explicitly targeted only towards Descartes, it would then at least partially miss its point. The existence of the Wolffian interpretation shows that there was a tradition of reading Cartesian sentence as a syllogism and that Kant was probably talking to representative of that tradition.

In addition to methodology, Wolff also uses his Cartesian starting point to ground his ontology, but this will be an issue I shall deal next time. Indeed, I shall probably be spending quite a while with the work: after all, the first German book on metaphysics deserves it.