Further reflections on Jean Guyon's conversion experience:
There is a sort of inward experience, which is not only intellectual, but which, to indicate to what part of the intellect it belongs, may be described more specifically as "apparitional." It is generally found among uneducated persons, but not exclusively; and it is so frequent in its occurrence, as well as important in its results and relations, as to authorize some notice. It consists, for the most part, in sights seen and sounds heard, not excluding anything which is addressed to the intellect through the external senses; and can justly be regarded as especially liable to illusion. It is here, perhaps, more than anywhere else, although all such experience may be accounted for to a considerable extent on natural principles, that Satan "transforms himself into an angel of light."
So far as this form of experience is concerned, the kingdom of God was erected within her “without observation." No sound was heard but that of the "still small voice," which speaks inwardly and effectually. There was no dream, no vision, no audible message. Her change was characterized, not by things seen, but by operations experienced; not by revelations imparted from without, and known only as existing without, but by affections inspired by the Holy Ghost from within, and constituting, from the time of their origin, a part of the inward consciousness.
— edited from The Life of Madame Guyon Volume 1, Chapter 7.