I recently met with the same fallacy in a leading article in one of the magazines. “The fact revealed by the spectroscope,” says the writer, “that the physical elements of the earth exist also in the stars, supports the faith that a moral nature like our own inhabits the universe.” A tremendous leap--a leap from the physical to the moral. We know that these earth elements are found in the stars by actual observation and experience. We see them as truly as we see the stars themselves; but a moral nature like our own--this is assumed and is not supported at all by analogy. The only legitimate inference from the analogy is, that as our sun has planets and that these planets, or one of them at least, is the abode of life, so these other suns in composition like our own, and governed by laws like our own, have planets revolving around them which are or may be the abode of beings like ourselves. If this “moral nature like our own” pervades our system, then the inference is just that it also pervades the other systems. But to argue from physical elements to moral causes is to throw upon analogy more than it will bear. Analogy is a kind of rule of three: we must have three terms to find the fourth. We argue from the past to the present and from the present to the future. Things that begin must end. If man’s life has been continuous in the past, then we may infer that it will be continuous in the future. Our earth has a moon; it is reasonable, therefore, to suppose that some of the other planets have moons. It is reasonable to suppose that there are other planets and suns and systems, myriads of them. It may be reasonable to think with Sir Robert Ball that the extinct or dark and burnt-out bodies in the sky exceed in numbers the luminous ones, as the non-luminous bodies exceed the luminous ones upon the earth. No man has seen live steam; when it can be seen it is dead; yet we know that it exists. We may complete a circle from a small segment of it. If we have two sides of a triangle, we may add the third. To find the value of an unknown quantity, we must have a complete equation and as many equations as we have unknown quantities. We can argue from this life to the future life only after proof that there is a future life.