Before getting into the difference between visions and physical manifestations, I have a rather lengthy introduction to describe one of my primary sources of information for this article. The Bible describes a number of experiences received by holy men of the past, who had divine encounters of various kinds. Some of these encounters were in dreams or trances, while others were during times of full consciousness. The primary difficulties in biblical interpretation of these passages are the vast difference in time, culture, geography, and in linguistics.