Philosophy 210/310
Early Modern Philosophy 
Andrew Mills' 
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Study Guide for Descartes, Third Meditation

Two ways to think about ideas

Descartes continues to think about ideas, and realizes that we can think about ideas in two ways:

As modes of thinking things (i.e., as mental occurrences, as things that are happening in my mind. In this way they are like pains or tickles) Conceived of in this way, ideas stand to thinking things in just the way that shape and size stand to corporeal things.

As representations (i.e., as ideas of something). Conceived of in this way, ideas are pictures, they have content and meaning. They are about something.

An analogy: You can think of what is on the chalkboard as a collection of chalk dust, or as a picture of a tree. You can think of what you see on the walls of the museum as a mound of oil paint, or as a picture of a ship at sea. Similarly, you can think of ideas as mental happenings, or as representations.

Even though Descartes is certain only that he has ideas, he realizes that the ideas he has are representational. They can be considered as pictures of other things (of course, he's not certain there are other things, but that doesn't take away at all from the representational nature of his ideas.)

Some Heavy-Duty Metaphysical Apparatus

We need to set out some of Descartes' technical apparatus before we can appreciate his attempt to show that God's existence follows from the fact that he has an idea of God.

Kinds of Being

Consider the following little argument:

  1. Suppose you are thinking about Pegasus
  2. Thinking about Pegasus is different from thinking about nothing at all (Indeed, thinking about nothing at all would just be not thinking at all, and thinking about Pegasus is different from not thinking at all.)
  3. So, in thinking about Pegasus, you are thinking about something.
  4. Therefore, when you think about Pegasus, there is something that you're thinking about.
  5. So, if you're thinking about Pegasus, Pegasus exists
 A strange and shocking conclusion: just by thinking about Pegasus, we can bring Pegasus into existence! But this would work for anything--so why not think about a million-dollar check in your wallet, or a the perfect mate. After all, thinking about them (according to this argument) brings those things into existence, and who wouldn't want the perfect mate to exist or a million dollar check in their wallet to exist?

Of course, we all know that thinking about Pegasus (or a check, or the perfect mate) doesn't make them exist. But how are we to express this point without going back on the above argument? The solution is to draw a distinction. In this case, a distinction between two ways of existing, or being. There's the way of being that (the argument shows) Pegasus has, and there's the way of being that you and I and the Eiffel Tower have (and which the million-dollar check, and the perfect mate, and Pegasus don't have). Descartes, following the medieval practice, calls these "Objective Being" and "Formal Being"

Objective being: Being as an object of thought

This is the sort of being that (this argument shows) Pegasus has. Other translators have rendered this as "representational reality". Anything that is thought of has objective being: it exists "in the mind", so to speak. Formal Being: Being independent of the contents of thought. This is the sort of being that you and I and the Eiffel Tower have. This is the sort of being that we really care about. When I want to know whether there's a million-dollar check in my wallet, I want to know whether such a check has formal being. And similarly with God. Why the term 'formal'? Perhaps because the model here is Plato's Forms--they exist whether or not anybody is thinking about them--indeed, they exist whether or not anybody is thinking at all. These are not exclusive categories. Some things, like Pegasus and the million-dollar check, only have objective being and do not have formal being. But many things have both: if you are thinking about the Eiffel Tower, then it has objective being. But the Eiffel Tower also has formal being, and your thinking about it doesn't take away from that. Presumably, there are (or can be) things that only have formal being--that is, things that exist, but are not the subjects of anyone's thought.

Notice also that we can talk of things that have objective being only when we are thinking about ideas as pictures or representations. If they were merely modifications of the mind, then we could not talk about objective being. We could not, because we could not talk about an idea being about anything. To see ideas as having content or being about something is to see them as more than just modes of thinking things.

Degrees of Reality

The second piece of the puzzle is the idea that among the things that are real, some things may be more real than others. Reality, in other words, comes in degrees. This is a strange notion, for we are used to thinking of reality as an 'on-or-off' property: something either is real or is not. Though it sounds strange, it is less strange once you see what is really at stake in ordering things by the amount of reality that they have.

Properties vs Substances

I have a mint-green bookcase. Given this, we can say the following:

A bookcase exists
The property of being mint-green exists A bookcase is a physical substance, and the property of being mint-green is a property. Both of these exist, but they are importantly different. The property of being mint-green exists only if there is a substance (my bookcase, your car, the candy in my pocket) which exhibits that property. If nothing (no thing--no substance) has the property of being mint-green, then the property doesn't exist. But my bookcase will continue to exist even if the property of being mint-green ceases to exist. My bookcase is not dependent on the existence of any particular color property (or any particular location property--it can be in my apartment, or in the street, or in a moving truck), but particular properties are dependent on the existence of substances. We can sum this up by saying that Properties exist dependently
Substances exist independently If this is the case, then it is natural to say that substances are "more real", "have more reality" than properties. We can put this point pictorially, with less reality at the bottom of the picture and more reality at the top:
 
Substances
 
Properties, Modes

Two remarks before we go on:

The notion that properties cannot exist independently is not universally accepted. We saw a discussion of this in the Second Meditation, when we reconstructed the Cogito argument in terms of the Substance Theory. There we saw the possibility of a Platonist account of properties whereby properties can exist independently of substances. On this point, however, Descartes was no Platonist.

In accepting the idea that substances can exist independently, are we thereby saying that a substance can exist without any properties at all? No, for we should understand the discussion above to be making the point that particular substances can exist independently of particular properties (my bookcase need not be any particular color, but it must be some color or other; my bookcase need not be in any particular place, but it needs to be someplace or other), but a particular property exists only if some particular substance exhibits it.

Perfections of Substances

Now let's focus on the substances. There are a lot of them: stones, carrots, frogs, dogs, people, angels and even God. These are all substances--they all have independent existence. But once we start thinking about it, we notice that there are differences among these substances in terms of their capacities and abilities. What can stones do? Not much. They just take up space. They're about as basic a physical substance as you can get. Of course, carrots take up space, but they do more: they can grow and reproduce. Stones can't do that. If we think of independent existence, taking up space, growth, and reproduction as (to use the medieval term) "perfections", then we can say that carrots have more perfections than stones do. And we can continue in this way for the other substances. What we get is the following elaboration of our first picture:

Infinite Substances
God              all perfections & infinitely so
Finite Substances
Angels              (below plus) immateriality

People                 (below plus) reason & self-awareness

Dogs                (below plus) adaptability 
& intelligence

Frogs               (below plus) movement & communication

Carrots                (below plus) growth & reproduction

Stones                 independent existence
Properties, Modes

The thought here is that some substances have more perfections than other substances (people have more perfections than frogs but fewer perfections than angels), and in this sense, we can rank some substances as being "more real" than other substances.

So, what the notion of degrees of reality is adverting to are these two, reasonably plausible thoughts: (a) some things exist dependently, and others independently and (b) some things have more abilities, capacities, or (in our term) "perfections" than others.

Now, notice also that this discussion of degrees of reality is combinable with the earlier discussion about the two kinds of being, and in two important respects.

First, we can compare the degrees of reality exhibited by things that have objective being. We can say that my idea of Pegasus has more reality than my idea of the Eiffel Tower.

Second, and importantly for Descartes, we can compare degrees of reality across the kinds of being. We can say, for instance, that Pegasus has more objective reality than the Eiffel Tower has formal reality. Of course, my idea of Pegasus has less formal reality than the Eiffel Tower has formal reality. (Why? Because ideas are modes of thinking things--mere properties--and so lowest on the "Great Chain of Being".) But Pegasus has a lot of objective reality--more objective reality than the Eiffel Tower has formal reality.

An analogy with different currencies might help here. I have 20 US dollars. You have 1000 Italian Lire. Now, you have more lire than I have dollars (Pegasus has more objective reality than the Eiffel Tower has formal reality), but I have more dollars than you have dollars--because, converted to dollars, 1000 lire is worth mere pennies, if that (the idea of Pegasus has less formal reality than the Eiffel Tower has formal reality). Ex nihilo nihil fit

"From nothing, nothing comes". This is an old principle--perhaps one of the oldest in Western philosophy, as it dates back to the pre-Socratic philosophers. The idea is a simple one: you can't get something from nothing.

 
For the English majors, this principle shows up in the first scene of King Lear. As you'll recall, Lear asks his daughters to say how much they love him, and in return he'll give them a piece of his kingdom. His first two daughters have heaped on the praise, and Lear has rewarded them handsomely. Now, Lear turns to his youngest and most-loved daughter, Cordelia:

Lear: ...what can you say to draw a third more opulent than your sisters? Speak.

Cordelia:  Nothing, my lord.

Lear: Nothing!

Cordelia: Nothing.

Lear: Nothing will come of nothing. Speak again.
The idea that nothing can come from nothing grounds the principle that for a given cause and effect, the cause must contain "everything" that is in the effect. To use Descartes' own example, if a stone comes to exist, then whatever created it must possess everything that is to be found in the stone. Why? Well, say this wasn't the case--say the stone contains something that the thing that created the stone didn't contain. Then the presence of that extra feature would violate the ex nihilo nihil fit principle, since it would have come "from nothing". In the Second Replies, Descartes says this: For if we admit that there is something in the effect that was not previously present in the cause, we shall also have to admit that this something was produced by nothing. As it shows up in the Third Meditation, it is the idea that there must be at least as much reality in the efficient and total cause as in the effect of that cause. (Paragraph 14) Let us (following Cottingham) call this the Causal Adequacy Principle. "Reality" here can be taken to refer to the "perfections" from the Great Chain of Being discussion, for it is there that we have the machinery of "more" and "less" reality.

Efficient Causes

When we talk about the 'efficient cause' of something, we are talking about the productive agency or power which gives rise to some change, or brings something into being. Descartes means the Causal Adequacy Principle to be about efficient causation, but it might be on stronger ground if it were about material causation--i.e., about the materials or ingredients out of which something is composed (girders, rivets, and concrete are the material causes of a bridge, but the architect and builders and engineers are the efficient causes of the bridge.) Pierre Gassendi, in the Fifth Objections, says that the Causal Adequacy Principle is on firmer ground if it is a principle about material causation rather than efficient causation

Putting it together

This all comes together in the following claim that Descartes makes at the end of the 14th paragraph:

There must be at least as much formal reality in the efficient and total cause of an idea as there is objective reality in the idea. Notice that we are thinking of ideas as representations (as pictures), we are distinguishing between objective being and formal being, we are distinguishing between degrees of reality, and we are claiming that ideas are caused--that they are effects and that they must have efficient causes.

The notion that ideas are caused is not so hard to swallow, but what is extremely interesting here is the claim that what can serve as the cause of an idea is a function of the content of that idea. What causes your idea of Pegasus must have formal reality, but it must have at least as much formal reality as Pegasus has objective reality. This means, for instance, that a knock on the head with a stone cannot cause your idea of Pegasus. This is because a stone doesn't have enough formal reality. It has more formal reality than the idea has formal reality (because, as we've noted, an idea is only a property and so has very little formal reality), but it has less formal reality than Pegasus as he exists in your idea has objective reality. Bringing this machinery to bear on the causes of ideas is Descartes' contribution to this issue.

Now, the proof that God exists is fairly straightforward:

  1. I have an idea of a completely perfect God.
  2. Only a perfect God has as much formal reality as my idea of a perfect God has objective reality
  3. So, (given the Causal Adequacy Principle as applied to ideas) a perfect God is the cause of my idea of God
  4. So, a perfect God exists.