questions involved in one controversy, and to determine the rights of all the persons who have any interest in the land, he must bring in all these holders of subsequent liens, so that a judgment may be given which shall foreclose their rights. To accomplish this end, these persons must be made defendants; and in that respect they are necessary parties—that is, necessary in order to attain the particular result desired. They are not, however, necessary to the decision of the main issues involved in the suit and to the granting of a decree. If we use language accurately, we shall call them proper parties, and shall thus distinguish them from the other class, without whom the judicial machinery cannot be put in motion. Every person who is rightly joined as a defendant in an equitable action, is, in a certain broad sense, a necessary party, because his presence is necessary to accomplish some particular end, and to make the judgment more complete than it otherwise would have been; but to use the term in this broad sense is to lose all the benefits of an accurate classification and of practical rules depending on such classification. To sum up: Necessary parties defendant are those without whom no decree at all can be rendered; proper parties defendant are those whose presence renders the decree more effectual; and all the proper parties are those by whose presence the decree becomes a complete determination of all the questions which can arise, and of all the rights which are connected with the subject-matter of the controversy. A practical test will at once fix the class into which any given persons interested in an equitable litigation must fall. If the person is a necessary defendant, a demurrer for defect of parties on account of his nonjoinder will be sustained; and conversely, if the demurrer will be sustained, the person is a necessary party. If the given person is merely a proper party, such a demurrer will not be sustained on account of his nonjoinder, although the court may undoubtedly, in the exercise of its discretion, order him to be brought in. § 331. The principal provision quoted at the commencement of the present Section, and which is the same in all the codes of procedure, is a general and concise statement of the doctrine which had long prevailed in courts of equity in relation to the joinder of defendants. As the language of this provision is permissive any person may be made a defendant, not must be it was evidently intended to embrace "proper" as well as "neces sary" parties within its requirement. The doctrine of equity, expressed in its most general form, is, that all persons materially interested, either legally or beneficially, in the subject-matter of the suit, should be made parties to it, either as plaintiffs or as defendants, so that there may be a complete decree which shall bind them all.1 Those whose interests are adverse to the claims set up by the plaintiff, and who would therefore naturally resist such claims, should be brought into the action as defendants. On the other hand, those whose interests are concurrent with the interests of the principal plaintiff who actually institutes and prosecutes the suit, should primarily be joined with him as coplaintiffs. But, as has already been shown in the preceding section, equity procedure is not strenuous in respect to this accurate division, and often permits individuals of the latter class to be made defendants, being satisfied if they are before the court so as to be bound by the decree. The persons who are interested in resisting the demands of the actual plaintiff, and who must therefore be defendants in the action, are separated, according to the nature of their interests and of their relations with each other, into two classes, those immediately interested, and those consequentially interested. When an individual is in the enjoyment of the subject-matter, or has a right, interest, or estate in it, either in possession or in expectancy, which is liable to be defeated or diminished by the plaintiff's success, he has an immediate and direct interest in resisting the plaintiff's demand, and is, in general, a necessary defendant. The interest here spoken of need not be personal and beneficial; it includes any estate or right in the subject-matter, legal or equitable, whether beneficial to the holder thereof or not.2 Numerous illustrations of this fundamental doctrine are given in the succeeding portions of this Section. § 332. If a person not thus immediately interested is, nevertheless, so related to the subject-matter and to the principal defendant that, upon the plaintiff's success, he will be liable to be proceeded against by such defendant, and to be compelled to make compensation, in whole or in part, for the loss, he is conse 1 See Story, Eq. Pl. §§ 72, 76 a. It has been suggested that this general doctrine should be stated as follows: All persons materially interested in the object of the suit should be made parties. See Calvert on Parties, pp. 1-11; Story, Eq. Pl. §§ 76 b, 76 c. 2 1 Dan. Ch. Pl. (4th Am. ed.) p. 246. quentially interested in the subject of the action, and is also, in general, a necessary, or at least a proper codefendant. Equity requires this class of persons to be joined as defendants, not because they will be directly affected by the decree when rendered, but because if the plaintiff succeeds against the principal defendant, the latter will then have the right to call upon them to reimburse him, wholly or partially, or to do some other act which shall, according to the nature of the case, restore or tend to restore him to his former position before the recovery against him. To avoid a multiplicity of actions, such persons should, in general, be brought into the suit in the first instance, so that their secondary or consequential liabilities may be determined and adjusted together with the main issues in the one decree.1 I shall now apply these very general statements of doctrine to the classes of cases which most frequently arise in actual practice. § 333. II. Actions to foreclose Mortgages. The first class or group of equitable actions which I shall take up, both because it is the most familiar and because it illustrates very clearly the general doctrine, is that of suits to foreclose mortgages. The statute distributes the persons who may be proper or necessary parties defendant into two divisions, those "who have or claim an interest in the controversy adverse to the plaintiff," and those "who are necessary parties to a complete determination or settlement of the questions involved therein." It is plain that the latter division is the more comprehensive, and in fact includes the former. Every person" who has or claims an interest in the controversy adverse to the plaintiff," is evidently “a necessary party to a complete determination of the questions involved therein; " but, on the other hand, it is equally evident that there may be persons" who are necessary parties to a complete determination of the questions involved, but who do not have nor claim any interest in the controversy adverse to the plaintiff." A single example will illustrate this position. The codes of several States require the assignor of a thing in action to be made a codefendant "to answer to the assignment" in a suit brought by the assignee. Of the two defendants, when this is done, the 1 1 Dan. Ch. Pl. (4th Am. ed.) p. 282; See, also, Story Eq. Pl. §§ 159, 162, 169, 169a, 172, 173, 176; Greenwood v. Atkinson, 5 Sim. 419; Wilkinson v. Fowkes, 9 Hare, 193; Knight v. Knight, 3 P. Wms. 66 333; Cosby v. Wickliffe, 7 B. Mon. 120; debtor alone has an interest in the controversy adverse to the plaintiff. The assignor has no such interest; he is not liable for the debt; his interest in the result is rather in accord with than in opposition to the plaintiff. He is, however, a necessary party to a complete determination and settlement of the questions involved in the suit. One of these questions is, whether the cause of action was in fact assigned to the plaintiff; and it is important to the rights of the debtor that this question be for ever settled in the single action. In the absence of any positive requirement of the statute, the assignor would not be a necessary defendant, because a judgment could be rendered against the debtor without the presence of the assignor. This example well illustrates my statement above, that one may be a party necessary to the settlement of all the questions involved in the suit, and at the same time neither have nor claim any interest adverse to the plaintiff. This evident distinction will aid us in discriminating between the necessary and the proper parties defendant in any given equitable action, for, as a general proposition, all those persons who have or claim an interest in the controversy adverse to the plaintiff are "necessary" defendants, if by "interest adverse" is intended an interest opposed to a recovery of judgment by the plaintiff ; while those who, in contradistinction to the former, are merely "necessary parties to a complete determination of the questions involved," are, in the main, "proper" defendants. § 334. These principles may now be applied to the class of actions under immediate discussion, those brought to foreclose mortgages. Those persons who own or have an estate in the land to be sold under the decree, and those who, in the original creation of the debt, or by any subsequent assumption of it, are debtors to the mortgagee, and therefore liable to a personal judgment for a deficiency, have an interest in the controversy adverse to the plaintiff, and are beyond doubt necessary parties, if the plaintiff desires to obtain all the relief which the law affords him, namely, of sale and personal judgment for deficiency. If, however, the plaintiff will be satisfied with a partial relief, and simply asks a decree for a sale without any personal judgment for a deficiency, the debtor, unless he is also owner of the land in whole or in part, is not a necessary defendant. The decree and sale must of course divest all ownership and titles to the land or any part thereof, or else there would be no sale but simply the show of one. But in order that the land may produce its full value, the decree and sale must go further than this, and must cut off all subsequent liens and incumbrances, and inchoate interests which are not titles but merely the seeds of titles. There is thus a threefold object of the judgment: (1) To divest the title of the present owner, and transfer the ownership to the purchaser. This is essential, and all persons who have any such title are necessary parties, for without them the whole action would be a nullity. (2) To cut off all liens and inchoate interests, so that the land can be sold at a greater advantage. This is of course not absolutely essential, for a sale can be effected without it. The holders of such liens and inchoate interests are proper parties. (3) To obtain a decree for any deficiency which may arise after the sale, against those persons who are liable for the mortgage debt. All such debtors are necessary parties if the plaintiff seeks to obtain this particular relief; but he may waive this relief and content himself with the sale and the proceeds thereof, in which case these mere debtors would not be necessary defendants. The foregoing principles have been adopted by all the courts. The doctrine The doctrine is universally established that in the equitable action to foreclose a mortgage by a sale of the mortgaged premises, all persons who own the land or any part thereof, all who have any interest therein vested or contingent, perfected or inchoate, subsequent to the giving of the mortgage, all who are owners or holders of any subsequent liens or incumbrances thereon, and finally all who are personally liable for the debt secured by the mortgage, may generally be united as defendants; and must be made defendants if the plaintiff seeks to obtain a decree affording him all the relief which the court can grant. As titles, interests, and liens prior and paramount to the mortgage are in no way affected by it or by the decree of foreclosure and the sale thereunder, the owners and holders thereof are neither necessary nor proper parties. § 335. While this general statement of the doctrine is universally accepted, there are some points of difference in its practical application. These differences will be found, upon careful examination, to arise, not from any doubt as to the general principle itself, but from a certain want of uniformity in the local law of the various States in respect to the nature of liens and incumbrances upon the land, and in respect to the nature of |