“There are,” says a poet as ingenious as profound,[1] “more things in heaven and earth than are dreamt of in our philosophy.” This sentiment, which Genius accidentally let drop, is in the main applicable also to the philosophy of our own day; and, with a slight modification, I shall be ready to adopt it as my own. The only change that is requisite to make it available for my purpose would be the addition--“and also between heaven and earth are there many things which are not dreamt of in our philosophy.” And exactly because philosophy, for the most part, does nothing but dream--scientifically dream, it may be--therefore is it ignorant, ay, has no inkling even of much which, nevertheless, in all propriety it ought to know. It loses sight of its true object, it quits the firm ground where, standing secure, it might pursue its own avocations without let or hinderance, whenever, abandoning its own proper region, it either soars up to heaven to weave there its fine-spun webs of dialectics, and to build its metaphysical castles in the air, or else, losing itself on the earth, it violently interferes with external reality, and determines to shape the world according to its own fancy, and to reform it at will. Half way between these two devious courses lies the true road; and the proper region of philosophy is even that spiritual inner life between heaven and earth. On both sides, many and manifold errors were committed even in the earlier and better days of enlightened antiquity. Plato himself, the greatest of the great thinkers of Greece, set up in his Republic the model of an ideal polity, which, in this respect, can not bear the test of examination. His design indeed finds, in some measure, its apology in the disorders and corruption which, even in his day, had infected all the free states of Greece, whether great or small. His work, too, by the highly-finished style of the whole, the vivid perspicuity of its narrative, its rich profusion of pregnant ideas and noble sentiments, stands out in dignified contrast to the crude and ill-digested schemes of legislation so hastily propounded in our own day. Still, it will ever remain the weak point of this great man. One needs not to be a Plato to see how absolutely unfeasible, not to say practically absurd, are many of the propositions of this Platonic ideal. Accordingly, it has ever been the fruitful occasion, not only among cotemporaries, but also with posterity, of ridicule to the ignorant and of censure to the wise. In this respect it can not but excite our regret that such great and noble powers of mind should have been wasted in following a false direction, and in pursuit of an unattainable end. The oldest philosophers of Greece, on the other hand--those first bold adventurers on the wide ocean of thought--combined together the elements of things, water, or air, or fire, or atoms, or, lastly, the all-ruling intellect[2] itself, into as many different systems of the universe.