Gottfried Leibniz practised materialist philosophy. It means believing in the possibility that plants and inanimate objects have consciousness or something similar to one. 

He believed that everything contains simple, immaterial, mind-like substances that help them sense the world around them.

Mill’s argument is considered an important contribution to Gottfried Leibniz’s philosophy of mind. A thought experiment involving entering a mill helps demonstrate that material objects, such as machinery or brains, cannot potentially have mental states. Only soul-like entities, or immaterial substances, can think or see. If this argument is successful, it will demonstrate not just that our thoughts are immaterial or that we have souls, but also that we will never be able to build a machine that can think or perceive.

Writings and Life

Gottfried Leibniz was born in the Lutheran town of Leipzig on July 1, 1646. Friedrich, his father, was a professor of moral philosophy at Leipzig University. Catherina Schmuck, his mother, was the daughter of a law professor. Leibniz was raised in a well-educated and orthodox Lutheran household. 

He developed an interest in classical literature and the writings of the Church Fathers at a young age.

Minds and the Mental States in the Gottfried Leibnizian Tradition

Gottfried Leibniz’s Materialist philosophy says that everything, even plants and inanimate objects, have an awareness or something approximating consciousness. He thought everything was made up of simple, immaterial, mind-like substances that could detect the environment. 

These mind-like things were referred to as monads. While all monads have a perception, only some are aware of what they perceive, i.e., only some have sensation or consciousness. Monads with self-awareness and rational perceptions are even rarer.

Leibniz’s Philosophy in Context

Many of Leibniz’s works are still unpublished. The Akademie edition, the official scholarly edition of his writings, only published his philosophical papers from 1663 to 1690, less than half of his career as a writer.

But unlike most of his predecessors, Leibniz did not write a famous work. There is no published work that represents the essence of his views. Leibniz published two books, Theodicy (1710) and New Essays Concerning Human Thought (completed in 1704 but not published until 1765). However, students can learn about his philosophy from his other writings, such as essays published in scholarly and popular journals, original works, and letters.

Fundamental Principles of Leibniz’s Philosophy

Our arguments are founded on two major principles, “contradiction… [and] sufficient reason” . The Principle of the Best, the Predicate-in-Notion Principle, the Principle of the Identity of Indiscernibles, and the Principle of Continuity could be added to these two main concepts.

The interplay between these principles is more complex than one might imagine. The Principle of the Best and the Predicate-in-Notion Principle is sometimes stated to ground Leibniz’s “two main principles”. In contrast, all four principles appear to act together in a circular implication system.

Metaphysics

1. Forms of Importance: One of Leibniz’s first intellectual undertakings was to figure out how to reconcile the Aristotelian philosophy taught at his Leipzig university and the new, mechanical philosophy advocated by intellectuals such as Galileo, Descartes, and Hobbes. 
2. Substance as a Whole Idea: Though Leibniz’s defence of incorporeal things allowed him to partially reconcile pre-modern and modern cognition, he still needed to explain what these substances were like. In Discourse on Metaphysics, chapter 8, Leibniz tackles the problem of identifying the individual substance.
3. Pre-Established Harmony and Causality: Since each substance is complete in itself and does not require the understanding of another substance, every finite substance is causally independent of all but God.
4. Idealism: Leibniz’s description of causality via pre-established harmony, his defence of incorporeal monads as the foundation of the physical world, and his view of substance as a complete concept contribute to his idealism style.
5. The Nature of the Human Body: The phenomenal nature of bodies follows Leibniz’s idealism. In other words, the physical world perceives monads’ perspective of it.
6. Final and Efficient Causality: Leibniz’s recovery of the concept of substantial form grew into his idealism monadic metaphysics and theory of pre-determined harmony. According to pre-established harmony, the activity of bodies must be described by other bodies, not by thoughts.

Ethics

Ethics is possibly the only conventional major content area of philosophy in which Leibniz is not widely regarded as having made a significant contribution. He does not, for example, have the same reputation as an ethicist as early modern intellectuals Spinoza, Hume, and Kant, nor does he have the same political philosophy influence as Locke and Hobbes.

1. Willpower and Intellect: In general, Leibniz’s approach to ethics is intellectualist in nature. He believed that moral excellence rises in tandem with knowledge. Happiness is also a result of improving one’s intellect. “It is self-evident,” he argues, “that mankind’s happiness consists in two things—having the power, to the extent permitted, to do what one will and knowing what, from the nature of things, ought to be willed.”
2. Charity and Justice: According to Leibniz, justice is an a priori science of the good. There is, in other words, a rational, objective basis for justice. Even though Leibniz wrote extensively on state positive laws, he does not see positive law as the foundation of justice. He criticises the belief that justice is founded solely on the will of those in authority, a belief that Leibniz frequently identified with Thrasymachus from Plato’s Republic, but more specifically with Samuel von Pufendorf and Thomas Hobbes.

Conclusion

According to Leibniz, there must be a “monas monad,” or God. The irreducible simplicity of a monad is its ontological nature. Monads, unlike atoms, have no material or spatial properties. They also differ from atoms in that they are entirely self-contained; therefore, interactions between monads are only visible.