IV. The speculations of Berkeley and Boscovich on the non-existence of matter; and of Kant and others on the arbitrariness of all our notions, are interested in, for they appear to be refuted by, the intuitions of cataleptics. The cataleptic apprehends or perceives directly the objects around her; but they are the same as when realized through her senses. She notices no difference; size, form, colour, distance, are elements as real to her now as before. In respect again to the future, she sees it, but not in the sense of the annihilation of time; she foresees it; it is the future present to her; time she measures, present and future, with strange precision,—strange, yet an approximation, instead of this certainty, would have been still more puzzling. So that it appears that our notions of matter, force, and the like, and of the conditions of space and time, apart from which we can conceive nothing, are not figments to suit our human and temporary being, but elements of eternal truth. LETTER IX. RELIGIOUS DELUSIONS—The seizures giving rise to them shown to have been forms of trance brought on by fanatical excitement—The Cevennes—Scenes at the tomb of the Abbé Paris—Revivals in America—The Ecstatica of Caldaro—Three forms of imputed demoniacal possession—Witchcraft; its marvels, and the solution. There have been occasions, when much excitement on the subject of religion has prevailed, and when strange disorders of the nervous system have developed themselves among the people, which have been interpreted as immediate visitings of the Holy Spirit. The interpretation was delusive, the belief in it superstition. The effects displayed were neither more nor less than phenomena of trance, the physiological consequences of the prevailing excitement. The reader who has attentively perused the preceding letters will have no difficulty in identifying forms of this affection in the varieties of religious seizures, which, without further comment, I proceed to exemplify. Every one will have met with allusions to some extraordinary scenes which took place in the Cevennes, at the close of the seventeenth century.