Until less than a century ago, the two prevailing views of dreams as well as of souls were that they are inconsequential (the scientific view) or of divine origin (the religious view). In either case it was assumed that they cannot be objects of rational inquiry. Similar views still prevail regarding mystical experiences and mysticism in general. Modern Western opinion, whether friendly or hostile, holds that the mystical falls squarely within the domain of the irrational.

Mr. Staal argues that mysticism can be studied rationally, and that without such study no theory of mind is complete....