- Only minds exist
- There are infinite minds
- Humans are not the only ones to have minds
- Everything has a mind
- Matter is made of minds
- Minds come in degrees, starting with matter (whose minds are very simple) and ending with God (whose mind is infinite)
- Reality is the set of all finite minds (or "monads") that God has created
- A monad is capable of perceiving other monads and of changing its state of knowledge
- Thought is just a kind of "perceiving".
- Some perceptions are "unconscious" (inert matter only has unconscious perceptions)
- When knowledge (awareness) increases, we feel pleasure. When knowledge decreases, we feel pain.
- All monads want to increase their knowledge
- We are born with the concepts of God and Mathematics
- Monads have free will but their actions have been determined by God
- There is no cause-effect relationship between events: God has pre-determined the harmony of the universe. Monads cannot influence each other. Monads are "clocks that strike hours together".
- Space is an illusion: we perceive as "close" what we "know" better (are aware of)
- "Lingua characteristica": universal language based on the laws of Logic
- The disparate disciplines of human knowledge can be unified by translating them into a universal language: a small set of primitive signs and a set of combinatorial rules to operate on them
- The answer to any question could be obtained by a mechanical procedure of applying the rules to the signs
- Many possibly worlds: ideas in the mind of God (we live in the best of possible worlds)
- Evil exists so that we can appreciate goodness