Themes
Key
LitCharts assigns a color and icon to each theme in Meditations on First Philosophy, which you can use to track the themes throughout the work.
Knowledge, Doubt, and Science
God and the World
Mind and Body
Intellectual Discipline
Summary
Analysis
The Meditator explains that the next pressing issue is to figure out whether he can prove the existence of physical objects. He notes that his ideas about such objects—like quantity, shape, position, motion, and duration—are clear and distinct. So are math and geometry concepts, like the properties of a triangle. (And these ideas would still be clear and distinct even if there weren’t any triangles in the real world.)
The Meditator’s most important metaphysical work is done: he has already established that God exists, that his own judgment is reliable, and that his clear and distinct perceptions are true. These conclusions provide the essential foundations for scientific knowledge. Now, he starts building this body of knowledge back up. He starts with the ideas that, in the First Meditation, he determined to be most certain of all: the basic principles of math, physics, and geometry.
Themes
In fact, this line of thinking leads the Meditator to another proof for God’s existence. The idea of “a supremely perfect being” is just as clear and distinct as that of a triangle. One property of such a being is that “he always exists.” Thus, God’s existence is as certain as the basic principles of math. Just like mountains and valleys, God and His existence are “mutually inseparable.” While it’s possible that there could just be no mountains in the world, it isn’t possible to imagine a being who is supremely perfect but doesn’t exist.
This proof for the existence of God, often called the “ontological argument,” is far simpler than the argument from the Third Meditation. A version of this argument dates back centuries, to the work of St. Anselm in the 11th century. Scholars have debated the relationship between these two proofs for centuries: some argue that they are merely redundant, while others argue that each proof serves a different function. However, most contemporary philosophers reject both.
Themes
Another objection is that it’s wrong to suppose that God is perfect in the first place. But this is inherent to the idea of God. Moreover, since nothing else has existence as part of its essence, there couldn’t be multiple supremely perfect Gods, and the Meditator clearly and distinctly perceives many other attributes of God, like the fact that He exists eternally. In fact, God’s existence is the most self-evident of all ideas.
The Meditator argues that perfect existence is just an inherent part of what God is, but most philosophers disagree. The most famous objection to Descartes’s ontological proof is Kant’s claim that “existence is not a real predicate,” meaning that existence is not the kind of quality that can be part of something’s essence. If we imagine a real ball and then imagine an imaginary one, we are really just imagining the same ball twice—the question of whether the ball exists has nothing to do with any of its inherent traits.
Themes
God’s existence is also the foundation of all other certain knowledge. The Meditator notes that sometimes he reaches clear and distinct conclusions through proofs, but then forgets the proofs and starts doubting the conclusions later on. But now that he knows for sure that God exists and isn’t a deceiver (which makes all clear and distinct perceptions true), he can continue to believe in his conclusions even after he forgets the proofs. In the past, much of his knowledge was unreliable, but now that he has proven God’s existence, the Meditator can “achieve full and certain knowledge” about God and mathematics for the first time.
The Meditator returns to the question of what God’s existence means for human knowledge and science. Before this point, he could only have certain knowledge in the moment when he had a clear and distinct perception of some conclusion—for instance, he could only know that a triangle’s angles sum to 180 degrees when he was actually thinking about the proof. But this poses a problem for science: how can we derive more complex truths from these basic principles if we have to go back over the proofs for the principles every time? Wouldn’t we have to stop believing in those proofs as soon as we stop thinking about them? And if so, wouldn’t they cease to be clear and distinct? This is why Descartes talks about God’s reliability giving us “full and certain knowledge.” Because God doesn’t deceive us, Descartes suggests, we can know that something we clearly and distinctly perceived (or proved to be true) yesterday is still true today. Thus, we can trust our past conclusions without having to repeat the whole process that led us to them.
Themes
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