delivered the opinion of the Court:

The question of the validity of these articles of agreement was elaborately argued by counsel on both sides, and with a voluminous array of authorities, both English and American. But in the view we take of this case, it is unnecessary for us to follow them.

We would be exceedingly reluctant in any case to declare void a provision made by a husband in good faith for the support of his wife, unless very good cause was shown for such declaration. As we have stated, we are relieved in this case from consideration of the charges and counter charges made by the parties; and the articles of agreement must be considered under the circumstances, to have been voluntarily and freely made, without fraud or coercion of any kind. Abundant consideration for such a provision might well be found in the duty imposed by law upon the husband to provide for the support of his wife. Assuredly it cannot be contrary to the policy of the law to do that which the law requires, whether the parties live with each other or live apart, and whether tire agreement is made in consequence of a separation that has already occurred or in contemplation of an impending separation. Whatever we may think of the validity or propriety of articles of separation in themselves, with reference to public policy, there can be no question *335about the propriety of provision by a husband for the support of his wife in any event; and we fail to find anything whatever in these articles of agreement beyond the simple covenant of the husband to provide a certain sum of money for the support of his wife. There is no question before us in regard to the propriety o'f the amount; and the only issue, therefore, is whether an agreement by a husband to support his wife is valid. The statement of this question is enough to dispose of it; for it is of no consequence whatever, apart from fraud or duress or some such consideration, what the immediate inducement for the agreement was to the husband. It is sufficient that the law requires him to do precisely what he did.

But we do not base our decision on this ground alone. By his own showing the complainant has demonstrated that he is not entitled to the intervention of a court of equity. For if the articles of agreement are void on their face as being opposed to public policy, it is well settled that a court of equity will not interfere to decree the cancellation or rescission of instruments of writing void on their face. Such instruments are void everywhere and under all circumstances, at law as well as in equity. And if the complainant’s contention is correct, there is no reason why he should not show the alleged invalidity in the two law suits which he shows to be now pending, or to have been pending, at the time of the filing of the bill. Equity will neither enjoin nor cancel instruments void upon their face; but only instruments the invalidity of which must be shown by extraneous testimony. This is a fundamental rule of equity jurisprudence. Peirsoll v. Elliott, 6 Peters, 95 ; Hannewinkle v. Georgetown, 15 Wall., 547.

The complainant, therefore, having abandoned the charges of fraud and duress in the procurement of these articles of agreement, and resting his case entirely on their alleged invalidity on the ground of public policy, is not entitled to the aid of a court of equity. The court in special term dismissed his bill; and we must affirm the decree of that court, with costs.