[2] The conduct of mankind differs from that of the brutes in being determined by anticipated sensations of pleasure and pain, instead of actual sensations. Hereby, in so far, human conduct is taken out of the sequence of cause and effect and falls instead under the rule of sufficient reason. By virtue of this rational faculty in man the connection between stimulus and response is teleological instead of causal. The reason for assigning the first and decisive place to pleasure, rather than to pain, in the determination of human conduct, appears to be the (tacit) acceptance of that optimistic doctrine of a beneficent order of nature which the nineteenth century inherited from the eighteenth. GUSTAV SCHMOLLER'S ECONOMICS[1] Professor Schmoller's _Grundriss_[2] is an event of the first importance in economic literature. It appears from later advices that the second and concluding volume of the work is hardly to be looked for at as early a date as the author's expressions in his preface had led us to anticipate. What lies before Professor Schmoller's readers, therefore, in this first volume of the _Outlines_ is but one-half of the compendious statement which he here purposes making of his theoretical position and of his views and exemplification of the scope and method of economic science. It may accordingly seem adventurous to attempt a characterisation of his economic system on the basis of this avowedly incomplete statement. And yet such an endeavor is not altogether gratuitous, nor need it in any great measure proceed on hypothetical grounds. The introduction comprised in the present volume sketches the author's aim in an outline sufficiently full to afford a convincing view of the "system" of science for which he speaks; and the two books by which the introduction is followed show Professor Schmoller's method of inquiry consistently carried out, as well as the reach and nature of the theoretical conclusions which he considers to lie within the competency of economic science. And with regard to an economist who is so much of an innovator,--not to say so much of an iconoclast,--and whose work touches the foundations of the science so intimately and profoundly, the interest of his critics and associates must, at least for the present, center chiefly about these questions as to the scope and nature assigned to the theory by his discussion, as to the range and character of the material of which he makes use, and as to the methods of inquiry which his sagacity and experience commend. So, therefore, while the _Outlines_ is yet incomplete, considered as a compendium of details of doctrine, the work in its unfinished state need not thereby be an inadequate expression of Professor Schmoller's relation to economic science.