contemplate
verb
look at thoughtfully; observe deep in thought
“contemplate one's navel”
consider as a possibility
“I contemplated leaving school and taking a full-time job”
think intently and at length, as for spiritual purposes
“He is meditating in his study”
reflect deeply on a subject
“I mulled over the events of the afternoon”
“philosophers have speculated on the question of God for thousands of years”
Source: WordNet 3.1, Princeton University