What a delightfully bizarre reading experience this has been. Who needs mind-altering substances when you have Leibnizian metaphysics? I doubt any psychoactive chemicals could take one on a trip into as queer realms as this work opens up. Surely among the strangest species of metaphysical cartography in existence, and this says a lot, since the category of metaphysical queerness is a very competitive category indeed.
And what is even more bizarre is how much sense this makes. Stranger still is that he is right on so many points, particularly in his sustained argument against reductionism, which still seems relevant to helping us gain traction on some of the dilemmas that plague us today, as inheritors of the Cartesian mechanist, reductionist paradigm for describing nature. His metaphysical project here basically outlines the conceptual parameters for an alternative, dynamic systems approach to the description of nature which intriguingly seems to avoid some of the contradictions inherent in our view. No wonder a version of the Leibnizian view is having a come-back, via systems theory.
First of all, I'll try to provide a working definition of a monad, as best as I understand it, since this seems to be a point of confusion among many (as it has been for me, for the longest time). A monad seems to have three functions in Leibniz's system.
First, a monad is an irreducible unit of being. In more Leibnizian terminology, it is a fully determinate individual substance. Numerical identity isn't enough to distinguish individuals, for Leibniz. Monads are, according to him, what supply us with the logic for singling out individual existents in their fullness.
Second, a monad is a fully determinate causal agent which possesses an internal principle for its change of states. I can't help but agree with Leibniz that, at the least, something like his view makes better sense of causality than does the Cartesian view which registers nature solely as an inert heap of automata. Automata make for notoriously poor causal agents. Not even efficient causation can be sufficiently grounded in mechanistic structures, because you'll always need to postulate a prime mover outside the system to set into motion the otherwise inert aggregate of parts that is nature on such a view. Leibniz's monads, at the least, are genuine causal agents.
Third, and most intriguingly, perhaps, a monad is a point of view in the universe. His is the only metaphysics I know of that acknowledges perspective as a fundamental metaphysical principle:
"Just as the same city viewed from different directions appears entirely different and, as it were, multiplied perspectively, in just the same way it happens that, because of the infinite multitude of simple substances, there are, as it were, just as many different universes, which are, nevertheless, only perspectives on a single one, corresponding to the different points of view of each monad (or individual existent)."
Fourth, monads are defined by their position in a universal web of relations and interchanges. Every individual part of the universe is, in his system, causally affected by the subtlest change in every other part, however distant. Moreover, monads seem to have an almost fractal structure:
"This interconnection or accommodation of all created things to each other, and each to all the others, brings it about that each simple substance has relations that express all the others, and consequently, that each simple substance is a perpetual, living mirror of the universe."
Monads can as such be said to be microcosms, with each part of the universe reflecting the whole. Thus, Leibniz rethinks the whole concept of the part/whole, or finite/infinite relation, that is arguably the basis of any paradigm. Leibniz even prefigures chaos theory by describing every monad, or part, as being defined by its relation to every other part. Also, being characterized by "a multitude in the unity" as they are, they evince a systems logic, and general laws seems to emerge from their collective behaviour.
Monads, in being fully individual and yet defined by their interconnection with every other monad or, part of the universe, provide the ultimate basis for conceiving the unity of phenomena. Without this unitary substantial basis, Leibniz argues, we're left with an incoherent conception of the world as a scattered, disconnected aggregate of parts. Such a metaphysical worldview, Leibniz argues, in offering us no basis for conceiving the underlying unity of this aggregate of phenomena, makes it impossible to explain the basis for scientific laws, which now become ontologically groundless. He argues that in the underdetermined mechanistic metaphysical picture, all unity, causal necessity, and law can only be accounted for as artifacts of the mind. Thus, his concept of an essentially unitary monad implies a critique of the Cartesian concept of nature as extension.
Leibniz proposes this redefinition of substance as monad as a solution to the problem of "the labyrinth of the composition of the continuum," ie, of accounting for the continuity of reality via any reductionist approach, in terms of the composition of the continuum through either mathematical points or atoms. This additive approach already presupposes a continuous basis to support the progressive addition of parts, whether conceived as points or as atoms. Cartesian mechanism, in particular, was plagued by the problem of the infinite divisibility of extension. This divisibility made it possible to specify stable structures or starting points for any chain of causation within the undifferentiated sea of extended matter. Monads, as irreducible units, offer an end to divisibility, while at the same time offering a basis for conceiving the cohesion of reality as well as for the beginning of any given chain of causation.
By far the most noteworthy part of his project, for me, was his effort to articulate what a first person view of the interiority of nature might look like. In other words, his is an effort to see nature from the inside out, from the level of the interiority of objects. This perspectival shift is what motivates his description of the monads, or fundamental units of existence, in mentalistic terms. His model for the universe is a pond filled with a density of microscopic life that is as inexhaustible as it is unfathomable. His whole system seems to imply a description in terms of a variety of anthropic principle, ie, what structures we must presuppose to exist in nature if we're to account for organic and mental phenomena.
The motto "Nature is alive" is, perhaps, Leibniz' philosophy in a nutshell. "There is nothing fallow, sterile, or dead in the universe, no chaos and no confusion except in appearance, almost as it looks in a pond at a distance, where we might see the confused and, so to speak, teeming motion of the fish in the pond, without discerning the fish themselves."
It is interesting that a great logician, and co-inventor of calculus, embarks on such an endeavour. From a post-Kantian, metaphysically-skeptical, contemporary standpoint, it must seem that Leibniz went off his rocker one day and decided to write the Monadology for diversion. Interestingly though, Leibniz identifies the function of this metaphysical project as one of supplying his logical, scientific, and mathematical systems with sufficient rational foundations without which these could not be fully rational. He claims that he is merely stating what Quine would call the ontological commitments we make in these disciplines (such as a commitment to the reality of possibles, of causality, and thus of fully determinate individual agents). Herein lies his defense for metaphysics as a whole. This defense, I think, deserves some attention, although I must confess that I am of a more mainline Kantian persuasion on the matter. Now that I think of it though, if taken as a knee-jerk response, even Kantianism can be a dogmatism. I guess, then, that the most pernicious dogmatism is supplied by the thing that purports to inoculate us from dogmatism, but I digress.
If you're curious, open-minded, and a fan of experiments with drastically different perspectival lens, try Leibniz on for size, just for the heck of it. At the least, a mind-trip is guaranteed wherein you'll feel someone just lit and dumped a bag full of firecrackers in your brain. You might be surprised to find what a great teacher a metaphysician can be in the art of seeing. I know I was. Try and look at the world -as if- monadic rather than mechanistic structures characterized the pattern of ultimate reality, and see for yourself the magic a metaphysical perspective shift can effect.