Descartes explains how the mind is separate with the body because the mind thinks. The body is described as a finite substance. He considers that his mind could have been in a different body at a different time. I would agree that that our mind and body could be using dualism. I am not one to argue something I could not be too sure of existing or not.
“To these it is certainly not necessary that I should attribute any author other than myself. ”
He is describing the lack of trust on other people’s opinions on any matter that is not able to be verified with his own senses. If he does not see a person standing in the corner but someone else says there is, he will not believe them. If he does believe them then he is nurturing a thought that is eminent.
The source of his ideas come from his own mind. However, he feels like his thoughts were strayed or biased into thinking the way it does by his social circle. Descartes believes a past life could be to blame for what ideas appear in his head.
“In the same way, when I perceive that I now exist and further recollect that I have in former times existed, and when I remember that I have various thoughts of which I can recognize the number, I acquire ideas of duration and number which I can afterwards transfer to any object that I please.”
“For how would it be possible that I should know that I doubt and desire, that is to say, that something is lacking to me, and that I am not quite perfect, unless I had within me some idea of a Being more perfect than myself”
His idea of a perfect idea would fit in the imaginary category. He would have to make an idea that is greater than himself which seems impossible. My idea for perfection would be impossible to reach. I can try to get really close to my idea of a perfect idea but there will probably be a better modification of my idea that comes after my time.