1 October 1997
...I didn't mean to give the impression that I'd tackled a narrow subject area for my D.Phil. Actually, my aim was very ambitious: to outline a metaphysic, to determine the relation between metaphysics and the philosophy of language and more besides! Realism was just the problem on which I got really 'stuck'.
Russell, in his brilliant book on Leibniz, is mainly responsible (although the idea was not his) for the view that all Leibniz's doctrines are based on the theory that all propositions can be analysed into subject-predicate propositions, and that in any such proposition, the predicate is included in the subject (I think you slipped up here, saying that the 'antecedent [is] "contained" in the consequent'). This indeed may be the proposition from which all Leibniz' metaphysics can be logically deduced. However, in my view it is a travesty of Leibniz's reasons for holding the views that he held.
There is more than one route to Leibniz' theory of monads, but the basic consideration is that it is intended as a solution to a serious problem facing an idealist or 'immaterialist' metaphysic; specifically, how one avoids the conclusion that, since not every object is actually perceived, the world must be riddled with holes. (An alternative solution is provided by Berkeley.) This is understanding Leibniz's theory 'dialectically'.
There is a crucial difference between a foundationalist epistemology, modelled on Descartes (but finding an alternative means for founding a world on the 'given' of sense perception to Descartes' God) and the search for a firm basis for a metaphysic, an axiomatic proposition from which the truths of metaphysics may be deduced as theorems. Descartes' 'Cogito' fulfils both roles, in serving as the basis for all human knowledge, and as the central axiom of mind-body dualism.
I do think that the quest for certainty in epistemology is a quest for a holy grail. It is important to face the sceptic, but I believe that the right response is dialectical, rather than attempt the impossible task of satisfying the sceptic's demand for a 'proof' of all knowledge claims.
There is something in what you say about mathematics being a wrong choice of paradigm. Descartes is very explicit in wanting to re-structure all human knowledge on the mathematical model. Plato saw mathematics as the best way of preparing students for knowledge of the eternal Forms, the only true objects of knowledge. — Yet to say this is merely to offer a diagnosis of a purported 'error'. Someone fixated by the idea of certainty will simply reject the diagnosis. You need something stronger to establish the concept of truth on a different foundation or paradigm.
— Could this be the main impulse behind the dispute between realism and anti-realism? Maybe!