When, about 1850, the phenomenon of "table-turning" was exciting the attention of Europe and ushering in the other phenomena since known as "spiritist", Allan Kardec quickly divined the real nature of those phenomena, as evidence of the existence of an order of relationships hitherto suspected rather than known-viz., those which unite the visible and invisible worlds. Foreseeing the vast importance, to science and to religion, of such an extension of the field of human observation, he entered at once upon a careful investigation of the new phenomena: "It is a most curious thing! My conversations with the invisible intelligences have completely revolutionised my ideas and convictions. The instructions thus transmitted constitute an entirely new theory of human life, duty, and destiny, that appears to me to be perfectly rational and coherent, admirably lucid and consoling, and intensely interesting. I have a great mind to publish these conversations in a book; for it seems to me that what interests me so deeply might very likely prove interesting to others."