One great reason why so many refuse to recognize mental as well as physical differences among races, is the common and favorite belief of our time in the infinite perfectibility of man. Under various forms this development-theory, so flattering to humanity, has gained an incredible number of adherents and defenders. We believe ourselves steadily marching towards some brilliant goal, to which every generation brings us nearer. We look with a pity, almost amounting to contempt, upon those who preceded us, and envy posterity, which we expect to surpass us in a ratio even greater than we believe ourselves to surpass our ancestors. It is indeed a beautiful and poetic idea that civilization is a vast and magnificent edifice of which the first generation laid the corner-stone, and to which each succeeding age contributes new materials and new embellishments. It is our tower of Babel, by which we, like the first men after the flood, hope to reach heaven and escape the ills of life. Some such idea has flattered all ages, but in ours it has assumed a more definite form. We point with pride to our inventions, annihilating--we say--time and distance; our labor-saving machines refining the mechanic and indirectly diffusing information among all classes, and confidently look forward to a new era close at hand, a millennium to come. Let us, for a moment, divest ourselves of the conceit which belongs to every age, as well as to every country and individual; and let us ask ourselves seriously and candidly: In what are we superior to our predecessors? We have inventions that they had not, it is true, and these inventions increase in an astonishing ratio; we have clearer ideas of the laws which govern the material world, and better contrivances to apply these laws and to make the elements subservient to our comfort. But has the human mind really expanded since the days of Pythagoras and Plato? Has the thinker of the nineteenth century faculties and perceptions which they had not? Have we one virtue more or one vice less than former generations? Has human nature changed, or has it even modified its failings? Though we succeed in traversing the regions of air as easily and swifter than we now do broad continents and stormy seas; though we count all the worlds in the immensity of space; though we snatch from nature her most recondite secrets, shall we be aught but men? To the true philosopher these conquests over the material world will be but additional proofs of the greatness of God and man's littleness. It is the vanity and arrogance of the creature of clay that make him believe that by his own exertions he can arrive at God-like perfection. The insane research after the philosopher's stone and the elixir of life may be classed among the many other futile attempts of man to invade the immutable decree: "Thus far, and no farther." To escape from the moral and intellectual imperfections of his nature,