JUDICIAL LEGISLATION. 179 are- enforced by the sovereign, it may be practically convenient to regard them as the sovereign's commands ; but in using this form of expression the cautions which have been suggested must not be forgotten. The question of this essay resolves itself, then, into this: How far is it the. proper function of the judge in our system to shape and develop the rules which constitute the mun- icipal law? II. (a) This question calls first for an examination of certain characteristic features of the English law. The com- mon law, strictly so called, must be taken as a type, though it will be desirable for purposes of comparison to refer to the pro- cess by which statute law is applied. This limitation of the dis- cussion to the common law makes it necessary to lay aside one subject of which notice must here be taken, namely, the great system administered by courts of equity. Growing up, not as a separate system of law, but merely as another mode of administer- ing the common law, and in this way of remedying its defects, it has by its operation given rise to a great body of rights, deriv- ative in their nature and based on its peculiar remedies. 1 If our object were a history of judicial legislation in the past, nothing would deserve more attention than the remarkable borrowing of equitable principles which for one cause or another has gone o*n in courts of law. To estimate the importance of these additions, without which our law would be a very different thing from what it is, it is only necessary to consider, as a single instance, the enormous reach of the purely equitable doctrine of estoppel. At the present time, however, the principles of equity are compara- tively fixed and definite, and the two systems of law and equity are to a great extent administered by the same courts and merged into one complete whole. Therefore, though their so-called fusion makes it none the less necessary to remember the abiding distinctions between the two systems, 2 much that is here said will have an application to both. Coming then to the common law of England and the method by which it decides a case, it is important to observe at the outset how the process presents itself to the judges, the persons in whose control it lies. Their testimony is unanimous. From the earliest times to the present day they have agreed in what Austin has 1 See Professor Langdell in i Harv. L. Rev. 55. 2 See 4 Harv. L. Rev. 394.