There has always been a philosophical problem about the nature of God.
He raised the question of black suffering as a philosophical problem.
For an example of a philosophical problem, see the God paradox.
He seemed to be wrestling with some huge philosophical problem.
"I have a philosophical problem with the idea," he said.
The God paradox is a good example of a philosophical problem.
"What you're dealing with is a very deep philosophical problem," she said.
His area of study was historical, literary, philosophical and religious problems.
But in the meantime, the front half of his attention was busy with a philosophical problem.
There they searched for answers to the political and philosophical problems of their time.