Some time ago there lived a guy that I think you should know;
Philosopher and clever mathematician, he was both.
His first name was René, though you can call him by Descartes,
This clever man who turned thinking into a form of art.
So many questions bubbled every day inside his head;
So many deep and daring thoughts kept him awake in bed.
“How can we know that we exist? How can we trust our eyes,
If when we sleep and dream of things they seem real in our minds?"
"Could we be living in a dream? Is any of this real?
Can we be sure of anything we see or touch or feel?
There must be something in this world that I can trust for sure;
There must exist at least one thought I know is true and pure!”
“But wait, that’s it!” He realized as he thought about this thought;
The fact that he was thinking was this truth that he had sought.
“I must exist, I must be real because, if I was not,
I don’t think I’d be sitting here thinking of all these thoughts!
If there is one thing in this world I know for sure, it’s this:
The fact that I am thinking also means I must exist!
So here I give my greatest thought, my idea so grand:
Cogito ergo sum, or I think therefore I am!”