thus attained the summit of vegetable powers and vegetable life, it will require, I think, no great stretch of the imagination to conceive that the fibrous irritability of animals, as well as vegetables, is the mere result of a peculiar arrangement of simple and unirritable material atoms."--"Hence, then, animal sensation, and hence, necessarily and consequently, ideas, and a material soul or spirit, rude and confined, indeed, in its first and simplest mode of existence, but, like every other production of Nature, beautifully and progressively advancing from power to power, from faculty to faculty, from excellence to excellence, till at length it terminate in the perfection of the human mind."[151] According to this theory, the mind is supposed to have a real existence, as a substance distinct from the grosser forms of matter, and capable even of surviving its separation from them. It is supposed to be "a combination of the most volatile auras or gases, diffused over the whole body, though traced in a more concentrate form in some organs than in others;" and it is described as "the very texture of that separate state of existence which the infallible page of Revelation clearly indicates will be ours." A form of the theory very nearly resembling this has been recently reproduced. It consists in representing the Mind or Spirit of man, not as a mere fleeting phenomenon of the brain, or an evanescent effect of its organization, but as a distinct substantive product, generated, indeed, from matter, and partaking, therefore, of its nature, but so exquisitely subtle and ethereal that it has no resemblance to the grosser materials of the body, and admits only of being compared with the Dynamides--the imponderable elements and forces of Nature. This "spirit" is generated in man by his peculiar organization, and especially by the action of the brain; it is capable of surviving the dissolution of the body, of retaining its individual consciousness after death, of passing into new spheres of being, and of rising from lower to higher states, according to a law of eternal progression. Such is the theory of Davis, the "Poughkeepsie Seer;" and such also, with some variations, is that of the author of "The Purpose of Existence."