“Man is arrogant in proportion to his ignorance.  Man’s natural tendency is to egotism.  Man, in his infancy of knowledge, thinks that all creation was formed for him.  For several ages he saw in the countless worlds that sparkle through space like the bubbles of a shoreless ocean only the petty candles, the household torches, that Providence had been pleased to light for no other purpose but to make the night more agreeable to man.  Astronomy has corrected this delusion of human vanity; and man now reluctantly confesses that the stars are worlds larger and more glorious than his own,—­that the earth on which he crawls is a scarce visible speck on the vast chart of creation.  But in the small as in the vast, God is equally profuse of life.  The traveller looks upon the tree, and fancies its boughs were formed for his shelter in the summer sun, or his fuel in the winter frosts.  But in each leaf of these boughs the Creator has made a world; it swarms with innumerable races.  Each drop of the water in yon moat is an orb more populous than a kingdom is of men.  Everywhere, then, in this immense design, science brings new life to light.  Life is the one pervading principle, and even the thing that seems to die and putrify but engenders new life, and changes to fresh forms of matter.  Reasoning, then, by evident analogy:  if not a leaf, if not a drop of water, but is, no less than yonder star, a habitable and breathing world,—­nay, if even man himself is a world to other lives, and millions and myriads dwell in the rivers of his blood, and inhabit man’s frame as man inhabits earth, commonsense (if your schoolmen had it) would suffice to teach that the circumfluent infinite which you call space—­the countless Impalpable which divides earth from the moon and stars—­is filled also with its correspondent and appropriate life.  Is it not a visible absurdity to suppose that being is crowded upon every leaf, and yet absent from the immensities of space?  The law of the Great System forbids the waste even of an atom; it knows no spot where something of life does not breathe.  In the very charnel-house is the nursery of production and animation.  Is that true?  Well, then, can you conceive that space, which is the Infinite itself, is alone a waste, is alone lifeless, is less useful to the one design of universal being than the dead carcass of a dog, than the peopled leaf, than the swarming globule?  The microscope shows you the creatures on the leaf; no mechanical tube is yet invented to discover the nobler and more gifted things that hover in the illimitable air.  Yet between these last and man is a mysterious and terrible affinity.  And hence, by tales and legends, not wholly false nor wholly true, have arisen from time to time, beliefs in apparitions and spectres.  If more common to the earlier and simpler tribes than to the men of your duller age, it is but that, with the first, the senses are more keen and quick.  And as the savage can see or scent miles away the traces of a foe, invisible to the gross sense of the civilised animal, so the barrier itself between him and the creatures of the airy world is less thickened and obscured.  Do you listen?”