Answer:
I think that the theme that best represents the given excerpt is suffering as a way of life. The excerpt hints that everyone always seeks to want more, starting from birth until one's death bed. And with their continuous search for their wants, they suffer since they are never satisfied with what they have. Thus, suffering becomes a way of life.
Explanation:
Which Event? Please Specify
This part of the thesis would be considered the topic, more specifically it would be considered the <em>introduction of the topic to study</em> since the thesis revolves around, I assume, Isaac Newton and you are offering a brief 'summary' of his life and accomplishments.
However if the reason to mention Sir Isaac Newton is to support an idea or a statement this could be considered a subtopic. It is subjective and directly related to the field of study you're doing the thesis for.
Hope this helps!