``The soul, by its interior vision, may see not only what is passing at a great distance, but it may also know in advance what is to happen in the future. The future exists potentially, determined by causes which bring to pass successive events. ``POSITIVE OBSERVATION PROVES THE EXISTENCE OF A PSYCHIC WORLD, as real as the world known to our physical senses. ``And now, because the soul acts at a distance by some power that belongs to it, are we authorized to conclude that it exists as something real, and that it is not the result of functions of the brain? ``Does light really exist? ``Does heat exist? ``Does sound exist? ``No. ``They are only manifestations produced by movement. ``What we call light is a sensation produced upon our optic nerve by the vibrations of ether, comprising between 400 and 756 trillions per second, undulations that are themselves very obscure. ``What we call heat is a sensation produced by vibrations between 350 and and{sic} 600 trillions. ``The sun lights up space, as much at midnight as at midday. Its temperature is nearly 270 degrees below zero. ``What we call sound is a sensation produced upon our auditory nerve by silent vibrations of the air, themselves comprising between 32,000 and 36,000 a second. . . . . . . ``Very many scientific terms represent only results, not causes. ``The soul may be in the same case. ``The observations given in this work, the sensations, the impressions, the visions, things heard, etc., may indicate physical effects produced without the brain. ``Yes, no doubt, but it does not seem so. ``Let us examine one instance. ``Turn back to page 156.@@@ ``A young woman, adored by her husband, dies at Moscow. Her father-in-law, at Pulkowo, near St. Petersburg, saw her that same hour by his side. She walked with him along the street; then she disappeared. Surprised, startled, and terrified, he telegraphed to his son, and learned both the sickness and the death of his daughter-in-law. ``We are absolutely obliged to admit that SOMETHING emanated from the dying woman and touched her father-in-law. This _thing unknown_ may have been an ethereal movement, as in the case of light, and may have been only an effect, a product, a result; but this effect must have had a cause, and this cause evidently proceeded from the woman who was dying. Can the constitution of the brain explain this projection? I do not think that any anatomist or physiologist will give this question an affirmative answer. One feels that there is a force unknown, proceeding, not from our physical organization, but from that in us which can think. ``Take another example (see page 57).@@@ ``A lady in her own house hears a voice singing. It is the voice of a friend now in a convent, and she faints, because she is sure it is the voice of the dead. At the same moment that friend does really die, twenty miles away from her. ``Does not this give us the impression that one soul holds communication with another?