The Argument from Doubt

Materialism: Human beings are wholly material—every part, including the mind, is material.Dualism: Human beings are not wholly material—the body is material, but the mind is immaterial.Interactionism: Minds and brains enter into two-way causal interactions.Cartesian Dualism=Dualism+Interactionism

Leibniz’s Law:x is Fx = yy is F

Leibniz’s Law:x is Fx = yy is F

Leibniz’s Law:x is Fy isn’t Fx ≠ y

I attentively examined what I was, and as I observed that I could suppose that I had no body, and that there was no world nor any place in which I might be; but that I could not therefore suppose that I was not… I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that “I,” that is to say, the mind by which I am what I am, is wholly distinct from the body.

I attentively examined what I was, and as I observed that I could suppose that I had no body, and that there was no world nor any place in which I might be; but that I could not therefore suppose that I was not… I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that “I,” that is to say, the mind by which I am what I am, is wholly distinct from the body.

I attentively examined what I was, and as I observed that I could suppose that I had no body, and that there was no world nor any place in which I might be; but that I could not therefore suppose that I was not… I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that “I,” that is to say, the mind by which I am what I am, is wholly distinct from the body.

I attentively examined what I was, and as I observed that I could suppose that I had no body, and that there was no world nor any place in which I might be; but that I could not therefore suppose that I was not… I thence concluded that I was a substance whose whole essence or nature consists only in thinking, and which, that it may exist, has need of no place, nor is dependent on any material thing; so that “I,” that is to say, the mind by which I am what I am, is wholly distinct from the body.

The Argument from Doubt

1) My body is such that I can doubt its existence.

2) I am not such that I can doubt my existence.

3) I am not identical to by body.

The Argument from Doubt

1) My body is such that I can doubt its existence.

2) I am not such that I can doubt my existence.

3) I am not identical to by body.

The Parody Argument

1) Clark Kent is such that Lois Lane can doubt he’s Superman.

2) Superman is not such that Lois Lane can doubt he’s Superman.

3) Superman is not identical to Clark Kent.