Leibniz and Spinoza

January 25, 2005

• A helpful distinction: clear and distinct. I have a clear idea of something if I can recognize instances of it. A distinct idea, however, requires that one be able to say what distinguishes it from everything else. Simply by being substances, we gain a clear idea of the notion of substance.
• Objection to Leibniz's argument for the simplicity of substances: The main argument for why the really real things are simples is that composites depend on the simples for their existence. But that does not imply that the composites are not substances. If one defines a substance as something that does not depend on anything else, then one is stuck with the view that only God is a substance.
• Unless perhaps one insists that there are different kinds of dependence. Think of the kind of dependence there is between a striking of a match and a flame. The two items do not even have to exist at the same time. On the other hand, think of the dependence between heat and molecular motion. This is a much more intimate dependence. One might almost say that there is no such thing as heat—there is just molecular motion. We might distinguish logical dependence and causal dependence. Substances cannot logically depend on anything else. In this way they differ from attributes and relations.
• Or, maybe, another way to put it is to say that there is a way of describing a substance such that a claim that it exists is made true by that substance alone and not by anything else. But if something consists of parts, then what makes it true that it exists is the existence of the parts.

· Here is another argument that Leibniz could have given, though he did not in fact.

o The universe is made of things that are objectively delineated, identifiable and countable.  What those things are is a question for further investigation.  Maybe they are natural things like human beings, horses, nettles, and their like.  Maybe they are solid things like human beings, a rock, the Empire State Building and an oak tree.  Maybe they are elementary particles such as electrons, photons and fermions.  What is important is that it is not just linguistic convention that settles what the things are, what they are identical with and how many of them there are, but objective reality settles it.

o Now, the Sunalex, which is the composite of me and the sun, is not objectively a thing.  The reason it is not a thing is that it is two things.  Now, of course one wants to retort: In one way the Sunalex is one thing and in another way it is two things.  But saying this misses the objectivity involved in identifying the things.  If in one way the Sunalex was one and in other two, then because we are looking for the things that are objectively delineated and objectively countable, we would have to have an objective fact of the matter about which of these it really is.  When we talk about “that reality, the Sunalex,” are we talking of one thing or two things?  Now, given that we must choose, it is evident that on the scientific grounds of what lends itself better to explanatory purposes it will be objectively better to talk of the Sunalex as two things rather than as one.  So there already is something we can say about the things.  No objective thing can be a composite sum of other things.  A heap of sand, then, is not a thing, for it is nothing but the mereological sum of the grains of sand.  Whether the grains of sand are things or not is a more difficult question.

o If composites are always things, there is an infinite number of ways of cutting up reality.  Instead of talking of me and you, I could talk of two composite beings: the sum of my left half and your left half, and the sum of my right half and your right half.  I could do this dividing up arbitrarily and in many ways.  This would mean that the world could be divided up in infinitely many ways, all depending on us.  But then there is trouble.  For instance, instead of describing a horse in terms of its heart, lungs, cells, etc., I could describe it in terms of other ways of dividing it up.  If I worked hard enough at it, I could probably show that a tree and a horse are the same thing, on Leibnizian principles.  Certainly, I can make the parts of a tree onto the parts of a horse.  Admittedly, they won’t interact exactly like the parts of the horse would, but this could be fixed perhaps—just think of these parts as nameless.  Anyway, Leibniz doesn’t buy this at the ultimate level of reality.  When we’re talking of that level, there is just one way to think of the universe.

· All of this looks at monads as ontologically basic things, as substrates. Leibniz distinguishes substances from accidents by saying that the accidents ultimately inhere in substances, and the substances do not inhere in anything. The “ultimately” is essential, because vivid might inhere in green which in turn inheres in a leaf. What this “inherence” is is not made clear in the letter to Burnett, but Discourse 8 talks about the concept of the substance containing the concepts of all the attributes, but not conversely. (This is a strange idea: one might think that it is the accident that cannot be conceived of without that which it inheres in.)

3. Section 3.  In the selections Rescher chose for section 3, we have a different way of looking at monads. Previously, the mark of a substance was its ontological position as a substrate. In the letter to Burnett, he says this gives a merely “nominal” definition—it gave a mark of substance, but did not tell us what substance really is like. Now he insists on activity and even life as a mark of substance.

· Leibniz compares them to substantial forms, and explicitly uses our soul as an example. 

· Substantial forms are a central item in Aristotelian and medieval metaphysics.  They do several things.  First of all, they unify parts into a whole.  Thus what makes my heart, lungs, legs, head, etc., be one thing is my substantial form.  Second, they are the principle of motion and development in the thing.  Why does my stomach digest?  It does so because of my substantial form, in its vegetative aspect.  Why does my mouth move now?  It does so because of my substantial form, in its intellectual aspect.  Thus, the substantial form of a human is in fact her soul.  The medievals thought all things had substantial forms. 

· If a plant is to be one thing, then it too must have a substantial form. 

o Otherwise, it’ll be a mere aggregate.  Here we get a subtler distinction.  There are mere composites, like the water in the pond together with the fish, whose reality derives entirely from that of its parts.  And there are what we might call substantial composites (my own term), which are unified by a substantial form.  There, the whole is more than the sum of its parts.  Note: That which unifies cannot be a mere part!  (An argument of Aristotle’s.)

o Leibniz thinks the distinction is only one of degree.

· The substantial forms of things are also their principles of activity.  The universe is made up of things.  But that is not all.  For, evidently, the things engage in various kinds of antics.  Depending on what we think the things are, they may emit radiation, or they may write philosophical treatises, or they may “spin” as electrons do, or they may gravitationally attract, or they may sit colorfully, or they may suffer passively.  So, the things do various kinds of stuff besides just existing. Leibniz distinguishes matter, which merely yields when pushed, from the true sources of activity—the substances. This gives him an argument that matter, by itself, cannot think.

• Moreover, if we look at a thing, say Leibniz or an electron, we see that the things it does change with time, though in a regular manner: Leibniz doesn’t go into an upright posture from a prone posture without any intervening steps, for instance.  Anyway, we want to explain because of what the changing activity occurs.  In each thing that originates its activity there must be that because of which it acts as it does.  That thing is the thing’s substantial form.  There is thus a close connection between what makes something be one thing and what causes it to act.
• One alternative to the notion of a substantial form was that God is the being causally responsible for all actions.  Malebranche.  Occasionalism.  Leibniz doesn’t buy this.

Sections 5-6.  Monads are neither naturally formed nor naturally dissolve.  The reason for this is that they lack parts.  This is a variant of a standard argument for the immortality of the soul.  The soul, it is argued, is simple.  Hence it cannot dissolve into parts.  The way things in nature cease to exist is by dissolution into component parts, and they come to be out of component parts.  But a completely simple thing can’t do that, L thinks.

• Therefore, either a monad has always existed and will always exist, or a miracle has occurred--something over and beyond the ordinary course of nature. 
• Kant talks of a second way something could dissolve.  It could just fade away.  But what would that mean?  That it exists less-and-less...
• The argument for the natural eternity of monads could also be made to run on the basis of the principle of continuity in nature that Leibniz certainly accepts.  This principle claims that all processes in nature happen continuously--though this is contingent, presumably.  There are no continuous degrees of existence, it might be claimed--a substance either is itself or it is not at all.  Thus, there would be a sharp discontinuity somewhere.  Think of a graph of the number of things existing, and jumps in it.  Of course one might just reject the principle of continuity in nature.