16. To this we reply, that we are so far from saying that the Creator could not place inhabitants in the other planets, that we have attempted to show what kind of inhabitants would be most likely to be placed there, by considering the way in which animals are accommodated to special conditions in their habitation. In judging of such modes of accommodating animals to an abode on other planets, as well as the earth, we have reasoned from what we know, of the mode in which animals are accommodated to their different habitations on the earth. We believe this to be the only safe and philosophical way of treating the question. If we are to reason at all about the possibility of animal life, we must suppose that heat and light, gravity and buoyancy, materials and affinities, air and moisture, produce the same effect, require the same adaptations, in Jupiter or in Venus, as they do on the Earth. If we do not suppose this, we run into the error which so long prevented many from accepting the Newtonian system:--the error of thinking that matter in the heavens is governed by quite different laws from matter on the earth. We must adopt that belief, if we hold that animals may live under relations of heat and moisture, materials and affinities, in Jupiter or Venus, under which they could not live on our planet. And that belief, as we have said, appears to us contrary to all the teaching which the history of science offers us. 17. And not only is it contrary to the teaching of the history of science, to suppose the laws, which connect elemental and organic nature, to be different in the other planets from what they are on ours; but moreover the supposition would not at all answer the purpose, of making it probable that the planets are inhabited. For if we begin to imagine new and unknown laws of nature for those abodes, what is there to limit or determine our assumptions in any degree? What extravagant mixtures of the attributes and properties of mind and matter may we not then accept as probable truths? We know how difficult the poets have found it to describe, with any degree of consistency, the actions and events of a world of angels, or of evil spirits, souls or shades, embodied in forms so as to admit of description, and yet not subject to the laws of human bodies. Virgil, Tasso, Milton, Klopstock, and many others, have struggled with this difficulty:--no one of them, it will be probably agreed, with any great success; at least, regarding his representation as a hypothesis of a possible form of life, different from all the forms which we know. Yet if we are to reject the laws which govern the known forms of life, in order that we may be able to maintain the possibility of some unknown form in a different planet, we must accept some of these hypotheses, or find a better. We must suppose that weight and cohesion, wounds and mutilations, wings and plumage, would have, either the effect which the poets represent them as having,