* * * * * The large space given to the statement of the purpose and drift of 'The Intellectual Development of Europe,' will allow only a brief consideration, in this paper, of the two great points presented by its author. These are, the question of the relative value of moral and intellectual truths in the progress of the human race; and the nature of the law of individual and social development. Both Professor Draper and Mr. Buckle affirm, and endeavor to support the affirmation with array of proof, that intellectual truths are more important and more concerned in the march of society, in the advancement of mankind, than moral ones; and both conclude that the great object of life, its final achievement, is intellectual culture and mental unfoldment in the individual and in the race. To the consideration of these points we will, therefore, direct our attention. The social, political, religious, and scientific development of the world proceeds under the operation of two grand antagonistic principles. One is the principle of Unity. The other that principle which is the opposite of unity, which we will call Individuality. The first tends to bring about coöperation, consolidation, convergence, dependence; the second to produce separation, isolation, divergence, and independence. Unity is the principle which tends to order; Individuality to freedom. The desire of order is the animating sentiment of conservatism. The love of freedom is the vital essence of progress. Unity is the static, and Individuality the motic force of human society. Both are inherent in the nature of things, and equally important as elements of a true social organization. Unity is allied to the affections, which are synthetic in their character; Individuality, to the intellect, which is mainly analytical, critical, and disruptive in its tendency. Unity is predominant in religion, which is static in its nature; Individuality, in science, which is primarily disturbing. In the distribution of the mental faculties, Unity relates to the moral powers, and Individuality to the intellectual; the former being, as both Mr. Buckle and Professor Draper have shown, more stationary in their character than the latter.