Matter being thus distributed, attraction causes it to aggregate in nebulous patches, which proceed to undergo a development similar to that described in Laplace's "Nebular Hypothesis." Our solar system, beginning in the form of a nebula, assumed a spherical shape and, as its constituent atoms sought its center, began to revolve. As the velocity of the revolution increased, the "centrifugal force" got the better of the centripetal, and a ring of matter was detached from the nebula's equator; this ring finally condensed into the planet Neptune. Shrinking in size, the nebula, in like manner gave birth to the other planets, including the earth, and finally arrived at the size in which we now know it as the sun. Similarly, during their condensation, several of the planets threw off satellites.[1]
In the following paragraphs Poe sums up the cosmic development and gives an account of the changes on the earth's surface:
In speaking, not long ago, of the repulsive or electrical influence, I remarked that "the important phenomena of vitality, consciousness and thought, whether we observe them generally or in detail, seem to proceed at least in the ratio of the heterogeneous." I mentioned, too, that I would recur to the suggestion; and this is the proper point at which to do so. Looking at the matter, first, in detail, we perceive that not merely the manifestation of vitality, but its importance, consequences, and elevation of character, keep pace very closely with the heterogeneity or complexity of the animal structure. Looking at the question, now, in its generality, and referring to the first movements of the atoms towards mass-constitution, we find that heterogeneousness, brought about directly through condensation is proportional with it forever. We thus reach the proposition that the importance of the development of the terrestrial vitality proceeds equably with the terrestrial condensation.
Now, this is in accordance with what we know of the succession of animals on the Earth. As it has proceeded in its condensation, superior and still superior races have appeared. Is it impossible that the successive geological revolutions which have attended, at least, if not immediately caused, these successive elevations of vitallic character—is it impossible that these revolutions have themselves been produced by the successive planetary discharges from the sun; in other words, by the successive variations in the solar influence on the Earth? Were this idea tenable, we should not be unwarranted in the fancy that the discharge of yet a new planet, interior to Mercury, may give rise to a new modification of the terrestrial surface—a modification from which may spring a race both materially and spiritually superior to man."[2]
The statement of Poe in this passage, that "heterogeneousness, brought about directly through condensation, is proportional with it forever," appears to contain the germ of Herbert Spencer's developed formula: "Evolution is a change from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity through continuous differentiations and integrations."[3] Noteworthy, also, is Poe's statement of the correlation between mental development and physical organization,
