<blockquote>Proofs are not wanting that among the philosophers there was not only an ignorance, but actual doubt, about the divinity. Diogenes, when asked what was taking place in heaven, answered by saying, “I have never been up there.” Again, whether there were any gods, he replied, “I do not know; only there ought to be gods.”
Source. Translated by Peter Holmes. From Ante-Nicene Fathers, Vol. 3. Edited by Alexander Roberts, James Donaldson, and A. Cleveland Coxe. (Buffalo, NY: Christian Literature Publishing Co., 1885.) </blockquote>