written expressly on the subject of a Plurality of Worlds, but the doctrine was maintained by almost all the distinguished astronomers and writers who have flourished since the true figure of the earth was determined. Giordano Bruno of Nola,1 Kepler and Tycho believed in it; and Cardinal Cusa and Bruno, before the discovery of binary systems among the stars, believed also that the stars were inhabited. In more modern times Dr. Bentley, Master of Trinity College, Cambridge, in his eighth sermon on the Confutation of Atheism from the origin and frame of the world, has maintained the same doctrine, and in our own day we may number among its supporters the distinguished names of Sir William and Sir John Herschel, Dr. Chalmers, Isaac Taylor, and M. Arago.

2

Under these circumstances the scientific world has been greatly surprised at the appearance of a work entitled Of the Plurality of Worlds, the object of which is to prove that our earth is the only inhabited world in the universe, while its direct tendency is to ridicule and bring into

1 In his work entitled Universo e Mondi innumerabili.

? This sermon was written from the information given him by Sir Isaac Newton in his four celebrated letters addressed to Dr. Bentley.

contempt the grand discoveries in sidereal astronomy by which the last century has been distinguished. Although it is not probable that a work of this kind, however ably it is written, and however ingenious may be the reasoning by which views so novel and extraordinary are defended, will influence opinions long and deeply cherished, we have thought it necessary, in defence of astronomical truth, as well as of the lessons which it teaches, to defend the doctrine of a Plurality of Worlds by the aid of modern discoveries, and to analyze and refute the objections which have been made to it in the very remarkable work to which we have referred.

CHAPTER I.

RELIGIOUS ASPECT OF THE QUESTION.

BEFORE Christianity shed its light upon the world, the philosopher who had no other guide but reason, looked beyond the grave for a resting-place from his labours, as well as for a solution of the mysteries which perplexed him. Minds, too, of an inferior order, destined for immortality, and conscious of their destination, instinctively pried into the future, cherishing visions of another world with all the interests of domestic affection, and with all the curiosity which the study of nature inspires. Interesting as has been the past history of our race,-engrossing as must ever be the present,-the future, more exciting still, mingles itself with every thought and sentiment, and casts its beams of hope, or its shadows of fear, over the stage both of active and contemplative life. In

youth we scarcely descry it in the distance. To the stripling and the man it appears and disappears like a variable star, shewing in painful succession its spots of light and of shade. In age it looms gigantic to the eye, full of chastened hope and glorious anticipation; and at the great transition when the outward eye is dim, the image of the future is the last picture which is effaced from the retina of the mind.

But however universal has been the anticipation of the future, and however powerful its influence over the mind, Reason did not venture to give a form and locality to its conceptions; and the imagination, even with its loosest reins, failed in the attempt. Before the birth of Astronomy, indeed, when our knowledge of space terminated with the ocean or the mountain range that bounded our view, the philosopher could but place his elysium in the sky; and even when revelation had unveiled the house of many mansions, the Christian sage could but place his future home in the new heavens and in the new earth of his creed. Thus vaguely shadowed forth, thus seen as through a glass darkly, the future even of the Christian, though a reality