【正文】 nd importance to justify their careful isolation and separate study. The writer is strongly of the opinion that the question must be answered affirmatively. Economics is the study of a particular form of anization of human wantsatisfying activity which has bee prevalent in Western nations and spread over the greater part of the field of conduct. It is called free enterprise or the petitive system. It is obviously not at all pletely or perfectly petitive, but just as indisputably its general principles are those of free petition. Under these circumstances the study, as a first approximation, of a perfectly petitive system, in which the multitudinous degrees and kinds of divergences are eliminated by abstraction, is clearly indicated. The method is particularly indicated in a practical sense because our most important questions of social policy hinge directly upon the question of the character of the natural results of petition, and take the form of queries as to whether the tendencies of petition are to be furthered and supplemented or obstructed and replaced. That such a theoretical first approximation is indicated in a theoretical sense, that it is the natural logical way of going at the problem, conforming to the workings of our thought processes, is sufficiently evidenced by the fact that this is what economists have always in fact done, ever since there has been such a science or such a social system to be studied. They have, to be sure, been criticized for doing it, and severely. But in the present writer39。 ., with what would happen under simplified conditions never realized, but always more or less closely approached in practice. But theoretical economics has been much less successful than theoretical physics in making the procedure useful, largely because it has failed to make its nature and limitations explicit and clear. It studies what would happen under perfect petition, noting betimes respects in which petition is not perfect。 it is a study in pure theory. The motive back of its presentation is twofold. In the first place, the writer cherishes, in the face of the pragmatic, philistine tendencies of the present age, especially characteristic of the thought of our own country, the hope that careful, rigorous thinking in the field of social problems does after all have some significance for human weal and woe. In the second place, he has a feeling that the practicalism of the times is a passing phase, even to some extent a pose。s Preface Part I Introductory The Place of Profit and Uncertainty in Economic Theory Theories of Profit。Risk, Uncertainty, and Profit by Frank H. Knight, . First edition, 1921. Hart, Schaffner amp。 Change and Risk in Relation to Profit Part II Perfect Competition Theory of Choice and of Exchange Joint Production and Capitalization Change and Progress with Uncertainty Absent Minor Prerequisites for Perfect Competition Part III Imperfect Competition through Risk and Uncertainty The Meaning of Risk and Uncertainty Structures and Methods for Meeting Uncertainty Enterprise and Profit Enterprise and Profit (continued) The Salaried Manager Uncertainty and Social Progress Social Aspects of Uncertainty and Profit Footnotes About the Book and Author Preface This series of books owes its existence to the generosity of Messrs. Hart, Schaffner amp。 that there is a strong undercurrent of discontent with loose and superficial thinking and a real desire, out of sheer intellectual selfrespect, to reach a clearer understanding of the meaning of terms and dogmas which pass current as representing ideas. For the first of these assumptions a few words of elaboration or defense may be in place, in anticipation of the essay itself. The practical justification for the study of general economics is a belief in the possibility of improving the quality of human life through changes in the form of anization of wantsatisfying activity. More specifically, most projects of social betterment involve the substitution of some more consciously social or political form of control for private property and individual freedom of contract. The assumption underlying such studies as the present is that changes of this character will offer greater prospect of producing real improvement if they are carried out in the light of a clear understanding of the nature and tendencies of the system which it is proposed to modify or displace. The essay, therefore, endeavors to isolate and define the essential characteristics of free enterprise as a system or method of securing and directing co 鰋perative effort in a social group. As a necessary condition of success in this endeavor it is assumed that the description and explanation of phenomena must be radically separated from all questions of defense or criticism of the system under examination. By means of first showing what the system is, it is hoped that advance may be made toward discovering what such a system can, and what it cannot, acplish. A closely related aim is that of formulating the data of the problem of economic anization, the unchangeable materials with which, and conditions under which, any machinery of anization has to work. A sharp and clear conception of these fundamentals is viewed as a necessary foundation for answering the question as to what is reasonably to be expected of a method of anization, and hence of whether the system as such is to be blamed for the failure to achieve ideal results, of where if at all it is at fault, and the sort of change or substitution which offers sufficient chance for improvement to justify experimentation. The result of the inquiry is by no means a defense of the existing order. On the contrary, it is probably to emphasize the inherent defects of free e