His strategy for overcoming the problems apparent in Cartesianism -- including Spinoza as a reductio argument against Cartesianism -- was to [once again] go back to the basic assumptions and modify these.
We've already seen this in Spinoza -- instead of attacking Descartes' system from the tail end (i.e., the specific conclusions which seem so bothersome because of their inconsistency, offensiveness to traditional morality, etc.), Spinoza begins with a different set of axiomatic starting points (i.e., the definitions of substance, etc.) and lands in a very different place.
This philosophical analysis, notice, has been immensely productive in the history of philosophy.
Ancient world: finally issues in an atomic theory
Modern world: we will see with Leibniz and Kant that this process leads to dramatic, even revolutionary insights about basic starting points -- starting points which, a century or two later, achieve wider application in especially scientific theory.
In Liebniz's case -- he moves us from a substance metaphysics to a metaphysics of force or energy. In Jones' words:
What if analysis showed that extension was a derivative concept and that the really basic concept in physics was a psychic concept? In this event, there would be a way of reconciling physics and the moral sciences. (221)
This also lifts up a second point: Leibniz retains the Cartesian project of attempting to hold together a modern physics with an ancient/medieval "moral" picture of human beings.
CONTRASTS with an atomistic (Hobbesian) "matter in motion" -- operates instead with a continuum analysable with the new infinitesimal calculus (invented by both Newton and Leibniz). (222) Notice that this further means a refinement of Aristotelian physics -- especially the notion of an entelechy.
At the same time, this means an explicit conjunction of physics with metaphysics:
[only if]...we unite metaphysical laws with the laws of extension, do we obtain the systematic rules of motion, as I might call them....A body which pushes another along must therefore always suffer a retardation such that neither more or less force is contained in the effect than in the cause. Since this law cannot be derived from the merely geometrical concept of mass, there must then be another basic principle immanent in bodies, viz., the force itself which is always preserved in the same quantity, although it is divided among different bodies. From this, then, I drew the conclusion that we must, in addition to purely mathematical principles...,recognize metaphysical ones. (223f.)
L. follows Spinoza in a way parallel to the development of atomism out of Parmenides: accepting the definition of "substance" (or Being), Leibniz argues that there must be a diversity of substance ("little Beings" or atoms) instead of one.
Apart from this diversity, the monads otherwise retain the characteristics of Spinoza's substance: the monads cannot be formed, decomposed -- or influenced by other substances -- they are "windowless."
More carefully:
"How do all these individual substances differ from one another?" They cannot differ in size or in space occupancy, for these concepts imply extension; extension cannot be used to explain force, since force, as we have seen, is a more basic concept than extension. The only other way they could differ would be in respect of thought, or in the quality of the psychic life.
Leibniz derived this conclusion from the general Cartesian principle that everything that is not body is mind [note the continued assumption of dualistic metaphysics]: If a monad is not a body, it must be a mind. Moreover, Leibniz believed that this was confirmed in experience: What we experience in ourselves as "being alive" is nothing but that drive or thrust that, as we have seen, Leibniz held it necessary to presuppose as the basis of physical movement and change. (224)
This force, moreover, can only be internal -- since, qua substances, the monads cannot be affected by external forces. (225)
This leads to a kind of vital pantheism:
Each portion of matter may be conceived as a garden full of plants, and as a pond full of fishes. But each branch of the plant, each member of the animal, each drop of its humors is also such a garden or such a pond....
Therefore there is nothing fallow, nothing sterile, nothing dead in the universe, no chaos, no confusion except in appearance; somewhat as a pond would appear from a distance, in which we might see the confused movement and swarming, so to speak, of the fishes in the pond, without discerning the fish themselves.
We see thus that each living body has a ruling entelechy, which in the animal is the soul; but the members of this living body are full of other living beings, plants, animals, each of which has also its entelechy or governing soul. (226)
As Jones points out, this basic conception provides the basis for resolving the apparent conflict between modern physics and ancient/medieval teleological conceptions -- though how this is so still needs spelling out in greater detail. At this stage, we can notice that, reminiscent of Spinoza, Leibniz has "solved" Descartes' mind-body split (and, thereby, the split between physics and teleology) by assuming from the outset that in fact the basic building blocks of the universe -- the monads as "teleological units of force" -- are the foundation of all that is: this builds teleology into the basic "stuff" composing the world. That is, like Spinoza, L. overcomes the Cartesian dualism by assuming unity (between physics and teleology) from the outset -- by changing from Descartes' substance metaphysics to a metaphysics of "energy." (Cf. Heraclitus in response to Parmenides.)
As Jones later puts it:
Thus the universe in its ultimate nature is a teleological system, not mrely in the Cartesian sense that God created it in accordance with His plan, but also in the sense that every element in the universe is itself a miniature teleological system, a reflection of the universe as a whole. Between monads there is no causality, but only a reciprocity resulting from God's preestablished harmony. Within every monad there is real causality, and this is of the nature of appetition, or desire. Hence the basic relation in the universe is not mechanical but purposive. These considerations permitted Leibniz to give an account of morality and religion in the traditional sense, according to a means-end scheme. (230)
(To do so, however, will result in the classical problem [apparent with Leibniz's precursors in this -- namely Parmenides and Spinoza]: the domain of physics -- of Galilean bodies in motion -- is not ultimately real -- but represents only the view from a certain level of consciousness: see below, p. )
This basic conception also appears to solve other knotty problems: to think of the human being as a monad not only preserves the teleological character of humanity (in conjunction with an apparently non-teleological physics) -- it further articulates the human "identity within diversity," (what Jones calls the diversity in unity) of
the human as a self (an identity which remains the same through time and change) which
experiences change (diversity of thought, experiences, etc.)
As Jones explains:
There is unity in that the thought is my thought; there is diversity in that my thought is always the thought of another -- of an object, a not-me.
My perceptions, my thoughts change; yet they are all my thoughts. And introspection also reveals the "principle" of their change. What causes my perceptions and thoughts to change is appetition, or desire. Naturally, desire does not always attain to the whole of the perception that it seeks, but it always attains some of it, and insofar as it does, we advance to fresh perceptions.
What is true of the psychic life of men is true, in varying degrees, throughout the whole universe. For the principle of continuity, which Leibniz introduced in connection with his revision of Cartesian physics, enabled him to formulate a doctrine of degrees of consciousness and so to project the unity-in-diversity we know in ourselves into a general metaphysical law. Consciousness...is not just a peculiarity of human minds. Consciousness is a continuum, and every monad is a focus of sentient experience (a feeling, a life) at some particular level in this continuum. Though there are monads at many different levels of consciousness (both below our minimum and above out maximum), every monad is a real individual just because, at whatever level of consciousness it operates, its experience is its own. (226f.)
This is to say: Leibniz -- like Hobbes before him -- installs the individual as the basic metaphysical truth of the universe. In this way, he not only follows Hobbes, but also Descartes and the generally modern focus on the (individual) self.
--> the hierarchy of monads, differentiated by degree of consciousness.
Of course, this sense of the individual as first of all a force-center of desire and appetition is not only Hobbesian (or Machiavellian -- or Augustinian) -- it recalls the Platonic notion of eros, the drive towards completeness, which Aristotle relocates precisely in the "entelechy" as it seeks to actualize its form (acorn --> oak): this Aristotelian sense is further appropriated in Thomas, as Jones comments.
But there is also a difference:
...Leibniz's emphasis was not on the terminus, not on what a thing becomes, but on what becomes. This was not only an expression of the individualism of the new age; it also ruled out the investigation of final causes in natural science.
Spinoza had also appropriated Thomas' drive to completion and had also reinterpreted it as self-fulfillment. But Spinoza held the drive to self-fulfillment to be the distinguishing mark of modes; Leibniz held it to be the essence of substance. Morever, Leibniz did not conceive of the drive under the aspect of various metaphysically distinct attributes, including "mind" and "body," all equally real and equally complete. In Leibniz's view, the drive is just what it is -- an unfolding of perceivings and desirings. What Spinoza held to be completely distinct languages, Leibniz held to be simply different levels of awareness in the monad itself. (227)
The question arises: what about (efficient) causality?
--> pre-established harmony among the monads:
Each monad is a living mirror, or endowed with internal activity, representative according to its point of view of the universe, and as regulated as the universe itself....Thus there is a perfect harmony between the perceptions of the monad and the motions of bodies, pre-established at the beginning between the system of efficient cuases and that of final causes.... (228)
This again involves an absolute determinism (articulated finally by Laplace, etc.).
In a way that may seem perverse, Leibniz appears to have argued that this pre-established harmony argues for the existence of God -- rather than assuming God from the outset and deriving a pre-established harmony therefrom!
L. further offers a version of the ontological argument: see Jones, p. 229.
And note that this proof further entails L's theodicy --
Because, from a rational standpoint, an infinite number of systems are possible -- the question becomes why just this one? Presuming that God is infinitely wise and powerful, we can be assured that God chose the best system possible - consonant with two demands: "to obtain as great a variety as possible, but with the greatest possible order." (Jones quoting L., 230)
Note as well what may be a fallacious argument:
[My critics have] raised objections...that I attributed too much to God and more than is possible. But [they] can state no reason why this universal harmony, which brings it about that each substance expresses exactly all the others through the relations which it has to them, is impossible. (230)
MATTER AND EXTERNALITY
...the Galilean bodies in motion are not real, for only monads are real, and no monad or aggregate of monads is a body. But it does not follow, because the bodies of physics are not ultimately real, that they are sheer illusion. What is called body is the way in which certain monads represent (or mirror) aggregates of other mondas. From a distance a cloud of dust looks continuous and solid, though it is in fact composed of tiny particles. So a relatively low-level monad (or a higher-level monad during a period of low-level awareness) represents the universe of monads as bodies in space. As the monad's consciousness rises, it comes to represent the universe more adequately; when and if it passes from the "confused thought" of perception to the clear and distinct thought of rationalism, it represents the universe more nearly as it is. That is, it comes to understand that what men call "bodies" are aggregates of monads of the same nature as it experiences itself to be.
Thus, according to Leibniz, externality is a confused awareness of otherness. Insofar as a monad is capable of any degree of self-awareness at all, it distinguishes self from not-self (How could it be aware of self except insofar as it is also aware of something else that it is not?). Self, that is to say, is felt to exclude what is non-self, and this exclusiveness is represented (at this level of awareness) as spatial externality. As men gain a clearer knowledge of the world, they come to understand that the real exclusiveness of self is not spatial, but rather, the exclusiveness of a unique experience. In other words, a monad is not distinguished from other things by being spatially outside them (for no monad is really in space), but by being a different life, a different focus of experience, a different perspective on the universe. (230f.)
--> Spinoza's unified substance vs. illusory individuality;
--> Kant's reduction of spatiality to an idealist base;
--> QM's suggestion that division is indeed a matter of perspective -- a perspective overlaid on what is indeed "one stuff."
Further Kantian dimension:
On this basis Leibniz could give an account of science that both validated it as far as it goes and showed that it requires supplementation by theology. (231)
Generally, what's at work here is a somewhat Platonic hierarchy of consciousness/being:
Each level of representation [from perception to science within the range of human levels of consciousness] reflects the order of the universe with a certain degree of adequacy. The higher the level of consciousness, the more adequate the representation, and hence the more precise the information obtainable at that level.
[....]
Science, properly speaking, emerges only when a level is reached at which the representations form a deductive system, such as mechanics. Though the concepts and theorems of mechanics are far more adequate representations than the sensuous "fire" of perception, they are still only phenomena, only representations. Hence physics is not the final explanation of the universe. It only tells (with much greater prcision, of course, than perception's "fire burns") what is happening; it does not tell why it is happening.
Hence, though mechanics is adequate in the sense that the information it yields is useful, reliable, and true, it is also limited. (231)
--> discussion of the contrast between the mechanistic account of Socrates sitting in the jail cell, rather than in Megara, vs. a teleological account.
Socrates -- and, of course, every other object of behavior -- is an aggregation of monads, the various lives of which form a preestablished harmony. Every such object may be looked at from the outside (as by an external observer) or from the inside (if one or more of the monads that constitute this aggregate happen to be self-conscious). Looked at from the outsdie, these various lives appear as a sequence of mechanically related bodily states. But this mechanism is nothing but the means by which the ends of the aggregated monads are realized. (232, my emphasis)
And (immediately following):
Observation of the mechanism itself and of the relations between its various parts will never reveal the desires of the monads. Any outside observer will find only related parts interacting according to siple, mathematically statable laws, for the desirings are inside the individual parts of the machine, that is, they constitute the innter lives (whether or not these lives are consciously aware of themselves is immaterial) of these parts. (232)
Quoting from Leibniz:
Perception and that which depends on it are inexplicable by mechanical causes, that is, by figures and motions. And, supposing that there were a machine so constructed as to think, feel and have perception, we could conceive of it as enlarged and yet preserving the same proportions, so that we might enter it as into a mill. And this granted, we should only find on visiting it, pieces which push one against another, but never anything by which to explain a perception. This must be sought for, therefore, in the simple substance and not in the composite or in the machine. Furthermore, nothing but this (namely, perceptions and their changes) can be found in the simple substance. It is also in this alone that all the internal activities of simple substances can consist. (232)
[recall here precisely the problem we saw with Hobbes: can a pure materialism "explain" the emergence of the observer? L's answer is no: the observer exists -- but eternally distinct from, if in pre-established harmony with, the materialistic, mechanistic world.]
This means, then, as Jones puts it -- there is no difference between Socrates and a billiard ball -- except that the billiard ball's dominant monad (so far as we know) has no self-consciousness. If it did, and if it could report on its inner life -- it would explain the world of its motions to us in teleological terms, while we, as outside observers, would see its motions entirely deterministically.
--> again, this appears to resolve the modern split between physics and teleology into a unity -- BUT
--> it does so by radically sundering the two domains (as will be further apparent in the discussion of requiring two principles of explanation) -- reflecting not only:
[Spinoza's similar distinction between intellectual understanding of the world vs. a confused and illusory perception of the world];
Descartes' dualistic split between mind // body, etc.;
and, still further back -- the doctrine of the two-fold truth which begins with Scotus;
(looking forward) this anticipates Kant's similar distinction between the view of the world from the standpoint of pure reason (which recognizes both the mechanistic, causally determined world of phenomena AND the realm of freedoms operating according to ends).
If reality were merely rational, we would need only one principle -- the principle of contradiction. But since the rational is only the possibly real, a second principle is needed....Because Leibniz held that what makes the possibly-real real is God's choice of the best, his second principle was teleological. He called it the "principle of sufficient reason."
The principle of contradiction yields what Leibniz described as "truths of reason"; the principle of sufficient reason, "truths of fact." The two principles, and the truths derived from them, supplement each other; any satisfactory account of things involves the use of both. Truths of reason are implicatory propositions like those of arithmetic and geometry, and they are absolutely necessary.... (234)
This only gets us, however, orders of relations which, while eternal and objective, are only possible, not necessarily real. For example,
...Euclidean geometry is real. There is nothing logically necessary about the fact that the real world is Euclidean. Some other geometry might just as well apply. Nevertheless there must be some reason why the real world is Euclidean rather than non-Euclidean. Since this reason cannot be rational, it must be teleological. (234)
And so, both the teleological and the mechanical account, the why and the how, must be combined in a complete account.
By showing that mechanics and teleology, far from conflicting, actually supplement each other, Leibniz believed he had demonstrated that the theory of monads "equally satisfies both science and religion." (235)
As well, he claims to have solved other knotty problems -- i.e., the problem of evil. Again,
God, according to Leibniz, had an infinite variety of possible worlds to choose from, and He chose the best of them. Since He had an infinite variety to choose from, His choice was unrestricted; since He chose the best, the imperfection of the actual world is not incompatible with His goodness. Because both His power and His knowledge are unlimited, His goodness is wholly preserved. (235)
Similarly (though less clearly, in my mind), the classical problem of freedom also finds a solution here:
Though what men do is completely determined (the present of every monad is "big with its future"), human conduct is not necessary. It is contingent, because it depends on a free choice of the best. (235)
PROBLEMS
Is God a monad? yes -- but then is the whole universe God's body? So it would appear -- but --> pantheism
More seriously, the problem of solipsism:
...the only monad I know is "me" -- my own soul monad, which knows itself. How, then, can I know that its states represent other monads? If I knew on independent grounds that other monads exist, I might argue that, by means of a preestablished harmony, I represent those others adequately. Preestablished harmony, in a word, does not prove that representation occurs; it only proves, assuming that representation does occur, that it is adequate. But how, shut forever inside myself by the exigencies of the substance dotrine, could I ever hope to find evidence for the existence of other monads or to show that my states represent anything at all? It would seem, then, that Leibniz really ended, like Spinoza, with one substance, the only difference being that whereas Spinoza's "one" was a self-transcending whole, Leibniz's was a whole-consuming self. But whether we have a world that has swallowed the self or a self that has swallowed the world seems almost a matter of indifference. In both cases, we are a long way from the kind of real world that the physicists supposed themselves to be investigating. (236)