Define Descartes’ idea of substance.

Descartes' idea of substance is a foundational concept in his metaphysical system, outlined in works such as "Meditations on First Philosophy" and "Principles of Philosophy." In Descartes' philosophy, substance refers to that which exists independently and does not depend on anything else for its existence.

Descartes identifies two fundamental types of substance: thinking substance (res cogitans) and extended substance (res extensa). Thinking substance encompasses the mind or soul, characterized by consciousness, thought, and self-awareness. In contrast, extended substance pertains to the physical world, including bodies and material objects, characterized by spatial extension and divisibility.

Crucially, Descartes maintains a dualistic distinction between mind and body, positing them as separate and irreducible substances. The mind and body interact, but their essences are distinct. This dualism is a response to the mind-body problem, attempting to reconcile the mental and physical aspects of existence.

Descartes' concept of substance contributes to the broader framework of Cartesian dualism, influencing subsequent philosophical discussions on the nature of reality, consciousness, and the relationship between mind and body. While his dualism has faced criticisms, Descartes' exploration of substance remains a significant and enduring aspect of early modern philosophy.