User:Yanssel/sandbox

Substance or Cartesian dualism
Most notably defended by René Descartes, substance dualism is the view that the world contains two fundamental substances: mind and body (by 'body', any material thing is meant).[REF: MEDITATIONS] Substances are understood to be entities that exist independently of one another (this is as opposed to properties, which are typically believed to require substances for their existence).[REF: SEP] It follows that mind and body do not depend upon one another for their existence.

According to Descartes, minds are essentially thinking things: that which cannot think is not a mind. This is as opposed to bodies, which are essentially material things. Given that they have different essences, Descartes concludes that they have no dependence upon one another, and are therefore different substances. Descartes reaches his conclusion about the essences of minds and bodies through his famous Evil demon thought experiment.

Argument for substance dualism
In an effort to find something he could know with certainty, Descartes attempts to doubt everything he thinks he knows. In doing so, he envisions an evil demon that can cast even his sensory experiences into doubt. Thus, Descartes argues, even his senses could be thoroughly deceived. Descartes then tries to imagine that the evil demon is also deceiving him about his own existence, and so he attempts to doubt that he exists. Yet, the very act of doubting, which is a form of thinking, affirms his existence. "I think, therefore I am" is the conclusion that Descartes derives from this exercise, which is the famous Cogito, ergo sum.

In the process of doubting, Descartes noticed he could envision himself without a body, but he could not envision himself without thought. From this, he concludes that thought, and not material existence, is what is essential to being a mind. Furthermore, it is clear that thought is not essential to bodies, but that they be material is. It is important to note that Descartes is only interested in establishing that minds and bodies are different substances and not that they exist independently in actuality.

This argument for dualism is an argument from conceivability. That it is conceivable that minds and bodies exist separately is enough to prove that it is possible, even if not actual.

Criticisms and responses
Criticism and response -Arnauld -Clear and distinct conceptions