Western civilazation (Leonardo da Vinci) - coming up with a thesis for my essay

I need help coming up with a Thesis for my essay, I know that I want to to talk about Leonardo da Vinci and how is was fascinated with the human body and how he had a hand in the study natural science or nature. Help me? i

OK why don't you try to start with "Vitruvian Man". Leonardo da Vinci had used this one as example to write about and study as well human proportion. He is not the first that had been studying human proportion,but is first to describe "Sfumato". Furthermore he is one of the greatest

scientist at that time and all the time at all. He is also one of the two best painter of the late Renaissance.
Mona Liza's smile is to common and boring, I suggest not to use this one. You could try whit the war machine or that one that is flying.

Have a luck and another question if you like

So i'm taking a Western Civilazation class ( HumanitiesII ) that i'm really enjoying, the problem is I have not been in school for about 20 years, and i'm a lilttle confuse on how to pick my subject and my Thesis for my essay. So here it goes.... subject: would be "

The influence of of reformation"
Thesis, How do we practice or do we value reformation as they did in the 1600's how is it the same or different? another thought is ...

Thesis, Do we still have the same beliefs as Martin Luther documented in the 1600's and how are we affected to by Luthernism?

please help me ~