'Contemplation is the greatest good,' was stated by Aristotle. The highest form of contemplation is possibly hapiness, combining it with a virtuas character. It aims at nothing outside of itself. It may aquire an amount of exploration and explanation just to understand what the statement is actually trying to say. We focus more on action and may refer contemplation as "doing nothing". The question that can be asked are: What is man's greatest good? What is the source of deepest happiness? and is there really a greater good and would it apply to everybody?
It leads up to Descartes 'cogito ergo sum' where he attempted to prove his existence as a thinking being, by thinking, 'I think, therefore I am'. There are also allot humourous alternatives made:
"I'm pink, therefore I'm spam"
"René Descartes was a drunken fart - I drink therefore I am".