What is a thesis or not, a PhD thesis, a professor thesis?

A thesis is not just a topic nor a fact, or merely
an opinion. 'A good thesis has two parts. It should
tell what you plan to argue and' and followed by
how will you argue with factual evidence of course,
not just because you think so or your Daddy thinks
so or your virtual friend or because you think what
you worship think so. See a good guide below:

Developing A Thesis
http://www.fas.harvard.edu/~wricntr/documents/Thesis.html

A PhD thesis is something substantial for doctoral level
work, not only interesting and substantial but novel too.
Not only PhD, occassionally a full professor may write
a thesis before turning it into a book. See the link below:

http://en.wikipedia.org/wiki/The_Clash_of_Civilizations