Monadology

Overview

The Monadology is twenty-five pages and ninety numbered paragraphs, written in French in Vienna in 1714, two years before Leibniz died. He wrote it for a particular reader, probably Prince Eugene of Savoy, and it was not published in his lifetime.

It is the most compressed major text in modern philosophy. Each paragraph is a few sentences, each depends on the ones before it, and there is almost no argument on display: Leibniz states conclusions he had reached over four decades and indicates the reasons in passing. He had worked out most of it in the Discourse on Metaphysics in 1686 and defended it at length in the Theodicy in 1710, and this is the summary.

That makes it easy to read and hard to understand. You can get through it in an hour and not grasp why any of it should be believed. The remedy is to read the Discourse first, where the same system is argued rather than asserted.

A word on the word. Monad comes from the Greek for unity, and Leibniz means by it a true unity, something that is one thing rather than a collection. His argument is that only such things are ultimately real, and that everything else is an appearance grounded in them.

The argument

Sections 1 to 7: what a monad is. The opening move is short. There are composite things. A composite is an aggregate of simples. Therefore there are simples, and these are the monads.

From simplicity everything follows. Having no parts, a monad has no extension, no shape and no divisibility. It cannot be formed by assembly or destroyed by taking apart, so monads begin only by creation and end only by annihilation. And nothing can be rearranged inside one from outside, since there is nothing to rearrange, which gives the most famous line in the book: monads have no windows through which anything could come in or go out.

Sections 8 to 30: what happens inside them. If nothing acts on a monad, it must still differ from others, or there would be no way for composites to differ. So each has qualities, and Leibniz identifies them as perceptions, the representation of the many in the one, and appetition, the internal tendency that carries it from one perception to the next.

Perception here does not imply awareness. A monad may have perceptions it does not notice; Leibniz calls these petites perceptions and illustrates them with the roar of the sea, which is made up of individual waves nobody hears separately. This is the first serious theory of the unconscious in European philosophy, and it was aimed at Locke’s claim that the mind is always aware of what is in it.

Monads are ranked by how clear their perceptions are. Bare monads have only confused perception. Souls have memory and feeling. Rational souls, or spirits, can grasp necessary truths and reflect on themselves, and it is this that lets us do science and know God.

Sections 31 to 48: the two principles. All our reasoning rests on two. The principle of contradiction, by which we judge false whatever involves a contradiction. And the principle of sufficient reason, that nothing is the case without a reason why it is so and not otherwise, even if the reason is unknown to us.

From sufficient reason Leibniz argues to God. The series of contingent things cannot contain its own reason, however far back it is traced, so the reason must lie outside the series in a necessary being. He adds a version of the ontological argument, with his own correction, that it works provided a most perfect being is possible, and he thinks it is.

Sections 49 to 62: how monads relate without interacting. Since no monad affects another, what looks like causation must be something else. Leibniz’s answer is pre-established harmony. God, in creating, coordinated every monad’s internal sequence so that they agree perfectly, like clocks set once and never adjusted. When a stone appears to break a window, both events unfold from within their own substances, in step.

Each monad expresses the whole universe, distinctly in what is near it and confusedly in what is distant, so every one is a living mirror of the world, and a sufficient intelligence could read the entire past and future off any single one.

Sections 63 to 81: bodies and souls. Every monad has an organic body, itself a colony of monads, which is why there is a natural world at all. Leibniz denies that there is any dead matter: every portion of matter is like a garden full of plants and a pond full of fish, and every branch and drop is another such garden. Living things are not generated or destroyed but transformed, growing and shrinking. Souls follow the laws of final causes and bodies the laws of efficient causes, and the two kingdoms agree.

Sections 82 to 90: the best world and the City of God. God chose among infinitely many possible worlds and created the best. Spirits, capable of knowing him, form a moral community, a City of God, which is the most perfect state under the most perfect monarch, and in it nothing good is lost and no sin goes unaccounted. Leibniz ends on this note, and it is the part that made him a target.

How to read it

Read the Discourse on Metaphysics first. It is the same system with arguments attached and it is only sixty pages.

Then read the Monadology twice: once through for the shape, once slowly with a pencil, numbering the dependencies. Almost every paragraph is a consequence of an earlier one, and mapping that is the best way to see whether the system holds.

Mark where the assertions outrun the arguments. Sections 1 to 7 are close to a proof. Sections 14 onward, on perception and appetition, are much thinner, and the transition is where most objections start.

Read Voltaire’s Candide afterwards. It is aimed squarely at the best of all possible worlds, and it is worth deciding whether the satire hits Leibniz’s actual claim, which is about the best total arrangement of compatible goods, or a cheerfulness he never professed.

Read it against Spinoza, who started from similar rationalist premises and arrived at one substance rather than infinitely many, and then against Kant, who thought both had shown what happens when reason is allowed to build without checking what it can know.

Questions it raises

• The argument from composites to simples takes four lines. Is it as strong as its brevity suggests?
• If monads have no windows, what makes my perception of a tree a perception of that tree rather than a state that merely happens to correspond?
• Pre-established harmony explains the appearance of causation. Does it explain anything, or relocate the problem into the act of creation?
• Nothing is without a sufficient reason. Is that a truth about the world, a rule for inquiry, or an assumption we cannot do without?
• Leibniz says every state of a monad follows from its own nature and that this is compatible with freedom. Is inclining without necessitating a real distinction?
• If this is the best of all possible worlds, what would it take to refute the claim? Candide offers earthquakes. Is that an answer?