HARVARD LAW REVIEW. Vol. X. JANUARY 25, 1897. No. 6. I. — THE PLEDGE-IDEA: A STUDY IN COMPARATIVE LEGAL IDEAS. THE place in legal science of the subject commonly spoken of as Comparative Law is not easy to settle. Its settlement depends more or less on the analysis and grouping that one adopts for the various parts of legal science as a whole. Leaving for another occasion the question of classification from the point of view of jurisprudence, it has seemed worth while to attempt to illustrate here the significance of one view of the scope of the subject. The choice of topic for illustration was determined merely by casual circumstances creating an interest in this particular topic, and by the accessibility of material. The pledge-idea — briefly expressed, that of collateral security — is familiar enough in modern law. But it is distinctly an idea of modern times. The various known systems of law recognize it with various degrees of definiteness, according to the social stage which their development has reached, or had reached when arrested. The idea familiar to us has grown, in the history of the law, out of a very different one. The attempt here will be to go back to the primitive notion of that transaction, and notice its development and the traces it has left on the law as handed over to us in its later stages. To realize the root notion of the transaction, we may put ourselves in the place of the primitive traders and try to reconstruct the con- ditions of their traffic. In the ordinary case of barter between passing travellers, or at the monthly or half-yearly markets, A will 43
