We have now placed before our readers the substance of the arguments for and against a plurality of worlds, so far as developed in the essays of Dr Whewell and Sir David Brewster. The former is a work so replete with subtle thought, bold speculation, and knowledge of almost every kind, used with extraordinary force and dexterity, as to challenge the patient and watchful attention of the most thoughtful reader; and that whether he be, or be not, versed in astronomical speculations. Great as are the power and resources of the author, we detect no trace of dogmatism or arrogance, but, on the contrary, a true spirit of fearless, but patient and candid, inquiry. It is a mighty problem of which he proposes a solution, and he does no more than propose it: in his Preface declaring that, to himself at least, his arguments “appear to be of no small philosophical force, though he is quite ready to weigh carefully and candidly any answer which may be offered to them.” We feel grateful to the accomplished Essayist for the storehouse of authentic facts, and the novel combination of inferences from them, with which he has presented us; and we are not aware that he has given us just reason to regret confiding in his correctness or candour. And in travelling with him through his vast and chequered course, we feel that we have accompanied not only the philosopher and the divine, but the gentleman: one who, while manifestly knowing what is due to himself, as manifestly respects his intelligent reader. In several of his astronomical assumptions and inferences we may be unable to concur, particularly in respect of the nebulous stars. We may also well falter at expressing a decisive “Aye” or “No,” to the great question proposed by him for discussion, on scientific grounds, and independently of Scriptural Revelation; yet we acknowledge that he has sensibly shaken our opinion as to the validity of the reasons usually assigned for believing in a plurality of worlds. He remorselessly ties us down to EVIDENCE, as he ought to do; and all the more rigorously, because the affirmative conclusion, at which many heedless persons are disposed to jump, is one which, if well founded, occasions religious difficulties of a grave character among the profoundest and perhaps even devoutest thinkers. To suppose that Omnipotence may not have peopled already, or contemplate a future peopling of the starry spheres with intelligent beings, of as different a kind and order as it is possible for our limited faculties to conceive, yet in some way involved in physical conditions, altogether inexplicable to us, would be the acme of impious presumption. When we look at Sirius, in his solitary splendour in the midnight sky, pouring forth _possibly_ fifty times the light and heat of our sun, upon a prodigiously greater planetary system than our own, it is natural to conjecture whether, among many other _possibilities_, it may be the seat of intelligence, perhaps of a transcendent character.