The Concept of a Person
Two arguments about the self are being given.
1. I think "I exist" : therefore an enduring being exists
2. I think "I exist": therefore a being with all my mental activities exists.
Both inferences from arguments about the cogito are highly problematic
I am thinking now
     why does that show: I will exist forever?
	
     how could it?
I am thinking
     why does that show: my mind with all my powers exists
Reply: What Descartes seems to think is that only a being with properties mentioned in 1, 2 above can make statements
     Not, say, someone who just makes isolated statement
Why ? 
     here I spell out Descartes' purpose in a way he doesn't
	
Cogito argument really is an argument about persons
     and D believes that persons are substances. they exist forever
Activities of a thinking being (see Perry/Bratman, 120 left column):
Doubting, understanding, affirimg, denying, willing, refusing, imagining, sensing
The soul can do all of these things.
Imagination not part of my nature
Now we have the link back to lst Med. 
     Imagination is untrustworthy