pronounced the judgment of the Court. The plaintiff sues this action by guardian. The authority of the guardian is, by a proper plea in abatement, directly denied. Issue being joined on this plea, the only question for our determination is, whether the person claiming to be guardian is authorized to maintain this action for the plaintiff.
The letter of guardianship and the bond for the faithful performance of the trust, approved by the judge of probate, were undoubtedly prima facie evidence of the appointment of the guardian. But they were not conclusive. The defendant might show, that though in form they were correct, yet in substance they were defective and void. It appears from the records of the probate court, copies of which were introduced by the defendant, that the application for the appointment of a guardian and the order of inquisition, contained the name of Sarah Conkey, though the return of the selectmen and all the subsequent proceedings in the probate court contained the true name of *119Susan Conkey. But if these were the only defects, especially if notice had been given to the right person and there was no mistake as to identity in any stage of the proceedings, we doubt whether this misnomer would be a fatal error.
It further appears, that no notice was given to the plaintiff, of the inquisition of the selectmen or of the proceedings before the judge of probate, and that there was no adjudication that she was non compos or that a guardian be appointed. She was thus deprived of the management of her property and, to some extent, of her liberty, without an opportunity to object or be heard, and without any formal judgment. These are undoubtedly fatal defects, and render the whole proceeding unauthorized and void. It was so adjudged in Chase v. Hathaway et al. 14 Mass. R. 222 ; Wait v. Maxwell, 5 Pick. 217; and Hathaway v. Clark, ibid. 490. And in the last case, it was nolden, that the healing influence of time, after a lapse of thirty years, could not cure the infirmity.
The appointment of the. guardian being a nullity, it cannot authorize him to do any act which would bind his ward. Even an executive officer, to whom the guardian was likened in the argument, cannot justify under a void precept. And although the letter of guardianship produced by the plaintiff was sufficient prima, facie, yet we can discover no principle by which the defendant should be precluded from showing its invalidity.
But the plaintiff’s counsel contend, that although the appointment of the guardian is invalid, and although the ward is not bound by it, yet that the defendant should not be allowed to deny the existence of the guardianship. This is the ground which has been mainly relied upon, and which has been pressed upon us with great ingenuity.
It is very clear that the legal doctrine of estoppel does not apply, and it is not pretended that the defendant is technically estopped from denying and disproving the guardianship. But the plaintiff’s counsel argue that here is an equitable estoppel ; by which, I presume, is meant, that the defendant, by his acts and declarations, has so recognised the existence of the guardianship, that he ought now to be bound by it, and precluded from denying it.
The acknowledgments of parties, whether made in express *120words or inferred from acts, are always competent evidence against them. Ordinarily they are open to explanation or contradiction, and may be proved to be untrue by other evidence. Hall et al. v. Huse, 10 Mass. R. 39 ; Salem Bank v. Gloucester Bank, 17 Mass. R. 27. There are, however, some cases in which they are conclusive against the party making them.
Thus, admissions made with a view to a particular trial, and to save the necessity of producing proof of certain facts, whether made by parol, in writing or on record, are conclusive for the purposes of that trial. So, where the admission of the one party is the basis of the action of the other, or where the party making the admission derives an advantage from it, he shall not be allowed to contradict it although it be untrue So also, where persons assume to act in certain characters oi official relations to each other, they are precluded .from denying that they sustained these characters and relations. In all these cases, the admissions and the actions upon them partake of the nature of contracts, and in that respect become binding on the parties. Good faith forbids a person who, upon his representation, has procured acts to be done or advantages to be conceded to him at the expense of others, afterwards to disavow them and annul a virtual contract growing out of them. He is equitably estopped from doing so inequitable a thing. 2 Stark. Ev. 28 to 34 ; Watson v. Threlkeld, 2 Esp. R. 637. Robinson v. Nation, 1 Campb. 245 ; Like v. Howe et al. 6 Esp. R. 20; Flower v. Herbert, 2 Ves. sen. 326 ; Lipscombe v. Holmes, 2 Campb. 441 ; Haviland v. Cook, 5 T. R. 655 ; 1 Saund. Pl. & Ev. 47 ; Doe v. Budden, 5 Barn. & Ald. 626 ; Williams v. Goodwin, 2 Carr. & Payne, 257 ; Watson v. Wace et al. 5 Barn. & Cressw. 153.
But we do not think it necessary to go further into the examination of these general rules, or to undertake to define their precise extent and limits. The doctrine of equitable estoppels has been learnedly, ably and fairly discussed by the plaintiff’s counsel. But we think a reference to the true question before us and the relation in which the parties stand to each other, will show its inapplicability.
The case comes before us upon the pleadings, which present the precise question, whether the person who commenced and *121carries on this action in the name of the plaintiff, is authorized to do so. He claims to do it in the character of guardian. He is not her legal guardian. But it is said the defendant has estopped or precluded himself from showing this fact.
The pretended guardian and the defendant treated together in relation to the plaintiff’s right of dower in certain land formerly conveyed by her husband to the defendant. They adjusted the claim which the guardian for the plaintiff set up, in a manner apparently fair and equitable, and the present note is the consideration given for the relinquishment of the right of dower. Now the question is not whether the defendant is precluded from denying the validity of that contract; but whether, because he treated with the guardian in that capacity then, he is now, after a lapse of many years, in a different transaction bound to admit his authority. The counsel, in their argument, seem to forget who the parties to the suit are. The guardian is not the plaintiff, but undertakes to prosecute the suit for her. The plaintiff was no party to the adjustment of the claim of dower; and never assented to it, or, as far as appears, knew of it. When the plaintiff sees fit, by herself or any authorized agent or guardian, to enforce that contract, the defendant will not be allowed to deny its validity.
Such a suit would be a ratification of the unauthorized act of the pretended guardian, and would give validity to this contract, which, to be binding, should be reciprocal. If judgment should be rendered for the plaintiff in this suit, it would form no obstacle to her immediate recovery of dower, if she chose to enforce her right.
This transaction is not to be distinguished from an ordinary case of agency where the agent exceeds his power or acts without any. The principal may ratify the unauthorized act or not, at his option. If he ratifies it, the other party is bound and cannot complain of the want of authority in the agent. But before it can be enforced there must be a ratification. A suit is a ratification. But it behooves the other party to see that the suit is duly authorized, otherwise it will avail nothing. The commencing the suit is a distinct and dissimilar act from making the contract. An authority to make a contract would not imply an authority to enforce it by a suit at law. So an *122admission, direct or implied, that an agent or guardian was authorized to make a contract, would be no admission that he was authorized to sue upon it; nor would it have a tendency to preclude him from denying the authority and requiring proof of it.
The defendant has, as we think, clearly a right to ascertain that he is legally called into court, before he answers to the merits of the demand. And we discover nothing in this case, more than in any other, to preclude him from requiring proof of the authority by which it was commenced and is carried on. The proof failing on this point, or rather negativing it, the plaintiff was rightfully nonsuited.
Judgment of Court of Common Pleas affirmed.