(Calef, 2015) Descartes, in his thought experiments, could conceive of the possibility of dividing his body, but he could not imagine the division of his mind. For example, you might advocate for someone who has an illness that has devastated their body, rendering them unable to physically interact with the world, but still has a completely agile mind, capable of interacting with the world that surrounds him through thoughts and thoughts. ideas, or that of a dementia patient whose mind is ravaged by illness but still physically functions normally. This lends credence to the argument that the body and mind are not the same, because if they were identical substances, the mind and body would show the same signs of illness.