Which philosophical doctrine is represented by Leibniz?

Leibniz is a major figure of modern rationalism, alongside Descartes and Spinoza. What sets him apart is his quest for complete, unquestionable knowledge, based on reason rather than experience.

Leibniz’s philosophy is distinguished by a unique metaphysics, centered on the concept of the monad, the indivisible and essential entity constituting reality. He maintains that God has fashioned the best possible world, orchestrating harmony between monads according to the principle of sufficient reason.

This article takes us on a journey through Leibniz’s thought, examining his key ideas, his vision of nature and thought, and his theological optimism.

Leibniz’s rationalism

The foundations of Leibniz’s rationalism

Gottfried Wilhelm Leibniz, a fervent rationalist, was convinced that human reason was capable of unlocking the secrets of the universe and attaining knowledge that was both universal and incontestable.

He drew a fundamental distinction between two types of truth: truths of reason, inherent and unchanging in all possible universes, and truths of fact, subject to circumstances and dictated by our experience.

The former are the domain of logic and mathematics, disciplines in which the understanding finds absolute certainties.

The latter belong to the realm of science, requiring observation and the application of metaphysical principles for their understanding.

The place of logic and metaphysics

Leibniz saw logic as a form of mathematics, enabling us to manipulate concepts and propositions by means of precisely defined rules. His invention of the infinitesimal calculus revolutionized the way we deal with infinitesimal variations.

He envisioned the creation of a universal characteristic: a symbolic language capable of formulating all thoughts and solving all problems. His metaphysics is based on the concept of substance, defined as a simple, active and inseparable being, which he calls a monad.

These innumerable monads form the substance of all that exists. Each monad, endowed with perception and appetence, with the capacity to receive and generate change, also possesses a unique identity and purpose, leading it to reflect the universe in its own way.

Pre-established harmony: Leibniz and the order of the universe

Leibniz put forward the idea that monads are independent in their actions, that they share no causal link, but are nevertheless in perfect harmony. This synchronicity is the work of God who, by choosing the best of all possible worlds, has created a universe of perfection and diversity.

God’s creation is based on eternal and constant laws, which give nature its coherence and splendor. The monads, endowed with an innate knowledge of these principles, align themselves with the divine will, ensuring the order and balance of the universe.

Principle of monadology

Monads: definition and characteristics

According to Leibniz, monads are the fundamental, indivisible elements that make up reality. They act autonomously, without depending on other elements, which gives them the status of substances.

They are also referred to as entelechies, emphasizing that they intrinsically possess the foundation of their activity and perfection. Endowed with perception and appetence, monads are in essence epicenters of force and knowledge, each reflecting universal harmony in their own way.

Monad interaction and world organization

Without parts or spatial dimensions, monads are unalterable and eternal. They remain isolated, unable to influence each other through direct interaction.

Leibniz explains the order and coherence of the universe in terms of a harmony pre-established by God, who orchestrates all things with the aim of creating the best possible world, rich in variety and perfection.

Thus, monads present different degrees of consciousness and clarity, forming a spectrum from the simplest to the most complex, some enriched with memory and feeling.

Leibniz’s spiritualist vision

A fervent spiritualist, Leibniz saw ultimate reality as spiritual rather than material. He challenged the mechanistic view of matter, reduced to extension and movement, and saw it as a manifestation of associations between monads. He denies the existence of the vacuum and atoms, asserting that the universe is composed of organized bodies, themselves aggregates of monads.

The human soul, a thinking monad, occupies a special place in his thinking, embodying the capacity for divine reflection and connection. Leibniz thus defends human freedom, anchored in moral and religious principles, and proposes a theodicy to reconcile the presence of evil with divine goodness.

Leibniz and philosophical optimism: the best of all possible worlds

Theodicy: justifying evil in the world

The philosopher Leibniz tackled a major challenge: explaining the presence of evil and suffering in a world created by a God who was both all-powerful and perfectly good. He called his approach theodicy, an attempt to defend divine justice and goodness.

According to Leibniz, there are three categories of evil: metaphysical evil, linked to the limits of creatures; physical evil, embodied in pain and death; and moral evil, associated with sin.

He affirms that these forms of evil are indispensable to the realization of the supreme good, namely the glorification of God and the happiness of man. Metaphysical evil enables the diversity and hierarchy of possible worlds, while physical evil contributes to natural harmony and beauty. As for moral evil, it makes human freedom and responsibility possible.

Optimism as a response to the problem of evil

Leibniz asserts that our world is the best of all possible worlds, distinguished by its perfection and rich diversity. He bases his argument on the principle of sufficient reason, according to which all existence has a reason for being, and nothing happens without a cause. He concludes that God, as the ultimate cause of all things, opted for the best possible scenario in creating the world, respecting all existing logical and moral constraints.

The existence of evil, according to Leibniz, is not based on a divine failure, but derives from the nature of a complex world. Evil is reduced to what is strictly necessary and counterbalanced by a higher good, in an act of distributive justice that ensures that each individual receives according to his or her actions and needs.

Criticism and contributions to Leibniz’s thought

Leibniz’s optimistic vision has provoked criticism and debate ever since its conception. Voltaire, for example, mocked it in his work Candide, illustrating through ridicule the vices and pains of the real world. Kant questioned the force of the principle of sufficient reason and the possibility of rationally justifying theodicy.

On the other hand, Hegel enriched Leibniz’s ideas by proposing that the world evolves towards an expression of the absolute spirit, introducing a dialectical and historical perspective. Popper also found value in Leibniz’s thesis, emphasizing the role of rational choice in shaping the world, while adding a dimension of chance and contingency.

Leibniz, the emblematic figure of rationalism, dedicated himself to the quest for universal, unshakeable knowledge, rooted in reason rather than experience.

He developed an original metaphysics around the concept of the monad, a simple, living entity constituting the essence of all existence. Leibniz maintained that God had designed the best possible world, orchestrating perfect harmony between monads on the basis of the principle of sufficient reason.

His work also addressed theodicy, an effort to defend divine goodness and justice in response to the dilemma of evil and sin. Although his optimistic vision provoked criticism and debate, it also made important contributions to the development of modern thought.