Unit 2: Spinoza and Leibniz
The construction of Rationalist Metaphysics.
Table of Contents
1. Benedict de Spinoza: Monism
Spinoza believed that Descartes made a mistake by dividing the world into two substances (Mind and Body). He argued that there can be only one infinite, self-caused substance.
Substance = God = Nature
Spinoza’s famous phrase "Deus sive Natura" (God or Nature) reflects his Pantheism. Everything that exists is simply a part of the one divine substance. God is not a creator outside the world; God is the world.
2. Attributes and Modes
If there is only one substance, how do we explain the difference between a thought and a rock? Spinoza used two concepts:
- Attributes: The essential nature of the substance. While God has infinite attributes, we only perceive two: Thought and Extension (Matter).
- Modes: The individual, temporary expressions of the attributes. You and I are "modes" of the attribute of thought and extension.
Parallelism: Mind and Body do not interact. They are like two clocks perfectly synchronized because they are just two different ways of looking at the same substance.
3. G.W. Leibniz: Monadology
Leibniz rejected Spinoza’s Monism and Descartes’ Matter. He argued that the world is made of an infinite number of simple, spiritual "force-centers" called Monads.
Nature of Monads:
- Windowless: Monads cannot be influenced by anything external. Everything they experience comes from within.
- Dynamic: They are not passive matter but centers of energy/soul.
- Hierarchy: From "Bare Monads" (rocks) to "Soul Monads" (animals) to "Spirit Monads" (humans) and finally the "Supreme Monad" (God).
4. Pre-established Harmony
If monads are "windowless" and do not interact, how does the universe work together so perfectly? Leibniz proposed Pre-established Harmony.
God, the master clockmaker, created all monads at the beginning of time to be so perfectly synchronized that when I will my arm to move (Mind), the monads in my arm move (Body) at the exact same moment, without any direct interaction.
5. Comparison: Substance in Rationalism
| Philosopher | Number of Substances | Relationship |
|---|---|---|
| Descartes | Dualism (2: Mind/Body) | Interactionism |
| Spinoza | Monism (1: God/Nature) | Parallelism |
| Leibniz | Pluralism (Infinite Monads) | Pre-established Harmony |