Positive evidence of ultimate success.
The fact that we are to-day capable of stating such problems in regard to the destiny of the universe seems to indicate something like an advance in the direction of solving them; thought is unable to advance upon reality beyond a certain point; the conception of an ideal presupposes the existence of a more or less imperfect realization of it. In the tertiary period no animal speculated about the universal society. A true conception of the ideal, if the truth about the matter could be known mathematically, would be found to possess, in all probability, an enormous number of chances of being realized; properly to state a problem is to have begun to solve it. A purely mathematical calculation of the external probabilities of the case does not, therefore, express the real value in the domain of intelligence and morality, because in matters of intelligence and morality, possibility, probability, and the powers upon which the realization of the fact depends, lie in thought which is a concentration of inner and, so to speak, living chances.
In especial when the infinity of space is taken into account.
Over and above infinity of number and eternity of time, a field of hopefulness lies in the immensity of space, which makes it irrational for us to judge too absolutely of the future of the universe solely from our experience of so small a portion of it as our solar, and even as our stellar system. Are we the only thinking beings in the universe? We have already seen that, without passing far beyond what science holds to be certain, one may even now reply in the negative. There very probably exists an infinity of cold or cooling stars, which have arrived at about the same point in their evolution as our earth; each of these stars is physically and chemically analogous to the earth, and they must have passed through analogous stages of vapourization, and condensation, and incandescence, and cooling. It is therefore probable that they have given rise to forms of organic life more or less analogous to those that we are acquainted with. In effect, the homogeneity of the organic matter of which our stellar system is composed (a fact which spectral analysis enables us to ascertain in regard to even the most remote stars) allows us to infer, by an induction which is not too improbable, a certain similitude in the most fundamental types of organic life. Analogous types of mineralization and crystallization must have given rise to analogous types of organization, although the number and richness of the forms that are possible increase as existence grows more complex. We do not see why the primordial protoplasm should in such and such a satellite of Sirius be especially different from that of our globe; nay, there may even obtain a certain cycle of forms and “living numbers,” as Pythagoras would say, that periodically recur. It is difficult in the actual state of science to conceive life as appearing except in some form of matter analogous to the cellule, and to conceive consciousness as otherwise than centralized in and manifesting itself by vibrations such as those to which our nervous systems are subject. Conscious life implies a society of living beings, a sort of social consciousness which the individual consciousness seems, in a sort, to presuppose. Organic and conscious life, the conditions of which are so much more determinate than those of inorganic life, must everywhere, in spite of differences in the circumstances, have assumed in the course of evolution forms that, in a number of respects, must have been analogous to animals and human beings such as we are familiar with. Perhaps the most general of the laws formulated by Geoffrey Saint-Hilaire on the correlation of organs might be found to hold good of the animals existing on the satellites of distant stars of the twentieth magnitude. In spite of the infinite variety of the flora and fauna of our globe, and the seemingly inexhaustible ingenuity that nature has displayed in varying their forms, it may reasonably be surmised that the difference between the types of life with which we are acquainted and those with which we are not acquainted is subject to certain considerable limitations. In spite of differences of temperature, of light, of attraction, of electricity, sidereal species, how different soever they may be from terrestrial species of living beings, must, by the necessities of the case, have been developed in the direction of sensitiveness and of intelligence, and have gone in that direction sometimes not as far as we, sometimes farther. Note also that even on our globe the excessively odd and monstrous types produced, like those of the tertiary period, as it were in obedience to a sort of apocalyptic imagination, have proved unable to maintain themselves. The most enduring species have generally been the least eccentric, the closest to a uniform and æsthetic type. It is not excessively improbable, therefore, that the universe contains an infinite number of human species analogous to humanity as we know it, in all essential faculties, although, perhaps, very different in the form of their organs and in the degree of their intelligence. They are our planetary brothers. Perhaps by comparison with us they are gods; and in that fact lies, as we have said, the kernel of possible or actual truth in the ancient beliefs in regard to the divine inhabitants of the skies.[162]
Objections answered.
But, it has been said, if other globes than ours are inhabited by intelligent and affectionate beings who live as we do upon the daily bread of science, these beings cannot be notably superior to us, or they would have given us before this time visible signs of their existence. To argue thus is not sufficiently to take account of the terrible power of space to imprison beings in infinite isolation. It may well be doubted whether beings of a relatively infinite intelligence, as compared with us, would not find their power unequal to dealing with such spaces as separate the stars. Our testimony on a question of the existence of such beings has no more value than that of a flower in the polar regions, or a bit of moss on the Himalayas, or a bit of weed in the depths of the Pacific Ocean, would have if it should declare the earth to be void of really intelligent beings on the ground that they had never been plucked by a human hand. If, therefore, the universe somewhere contains beings really worthy of the name of gods, they are probably so distant from us that they are as unaware of our existence as we are of theirs. They perhaps have realized our ideals, and the fact of that realization will perhaps remain unknown to us to the end.
Possibility of discovering inhabitants in other spheres.
It is to-day admitted that every thought corresponds to a certain kind of motion. Suppose that an analysis more delicate even than that of the spectrum should enable us to record and to distinguish, not only vibrations of light but the invisible vibrations of thought in distant worlds. We should, perhaps, be surprised to see that in proportion as the light and heat of the incandescent stars decrease, there by degrees arises consciousness, and that the smallest and most obscure stars are the first to produce it, whereas the most brilliant and enormous, like Sirius and Aldebaran, are the last to feel these subtler vibrations, but feel them ultimately with greater power, and develop a humanity with faculties and powers proportionate to their enormity.
Slowness of spread of civilization from star to star.