Philosophical Perspectives on Substance and Knowledge

Descartes' Philosophy: Substance and Mechanism

The attribute of infinity is that which cannot exhibit any change, so modes do not apply to this attribute.

Regarding matter, its attribute is extension. Modes are supported. Movement is primarily the mode of extended substance. The problem is that extension does not inherently involve movement, but movement is observed in extended substance. This leads to the conclusion that movement is not inherent to matter itself.

To explain this, something external to matter is needed, and Descartes introduces God. He states that when God creates the world, He introduces the necessary movement. Bodies then transmit movement to others through contact. This explains the mechanics of the world.

This is the origin of mechanism, which influenced much of the philosophical thought of the eighteenth and nineteenth centuries. Descartes' mechanism applies only to matter. He is not a materialist, as he recognizes the reality of spirit and the reality of God. Descartes initiated mechanistic thought but was not a materialist. He posited that the only link between matter and spirit is the human being, thus man is made of mind (thought) and matter (extension). Descartes believed that the pineal gland is the point where these two converge.

Views of Other Rationalists

Descartes' rationalism, while foundational, also encompasses other thinkers like Nicolas Malebranche, Baruch Spinoza, and Gottfried Wilhelm Leibniz, who offered their own views on these subjects.

• Malebranche's Ontologism

  Malebranche gives absolute priority to God. He argues that we perceive ideas through God. This is ontologism, requiring knowledge of the divine mind.

• Spinoza's Pantheism

  Spinoza defends pantheism. He is convinced that God exists by the argument of Saint Anselm. Pantheism asserts that there is no other being but God, as He is the only infinite being, and there cannot be two infinite beings. All other things are merely modes of that single infinite substance.

• Leibniz's Pre-established Harmony

  Leibniz created the theory of pre-established harmony, also accepting Saint Anselm's argument for God's existence. He posits that God has pre-arranged a perfect correspondence between body and spirit, ensuring they act in concert without direct interaction. Matter and spirit, therefore, cannot influence each other directly.

Views of the Empiricists

• Locke and Cartesian Division

  Locke, considered the founder of empiricism, adopted the Cartesian division of reality (spirit, God, matter). Empiricism emerged to analyze what we can know through experience.

  Locke stated that we know the spirit through intuition, and that God's existence, while not directly perceived, can be proven. Regarding matter, he argued that we know nothing of its intrinsic nature. All our knowledge of matter comes through sense perceptions, which are psychological phenomena. Therefore, referring to 'field data' implies discussing something mediated by numerous processes.