SALMON v. CLAGETT.—3 BLAND. 163

the proceedings then, on a plea; it may be established by proof on
the trial of the plea; or upon a full disclosure, and at the hearing.
For, certainly, no Court of justice, after the fact has been shewn,
and made to appear, should compel a defendant to answer, or give
relief to a plaintiff as to any matter of which it has no jurisdiction;
or where the plaintiff has no legal capacity to demand and receive
that which he asks Lempster v. Pomfret, Anib. 154; Forum Rom.
54. These are the grounds on which the rule is founded; and,
therefore can, in no way, be considered as exceptions to it.

*Let it, however, be supposed, that the case shewn by the
bill is one of which the Court has jurisdiction; and that the 144
plaintiff has a capacity to sue. Even then the plaintiff's inquiries,
concerning the case, can only be such as he may lawfully make of
the defendant, as being properly a defendant; and supposing him
to be interrogated as a mere witness. The plaintiff, in this respect,
places the defendant in the condition of a witness; and interro-
gates him for the purpose of obtaining evidence; or the defendant
is thus called upon, as it were, by a subpoena duces tecum, and
required to bring into Court certain documentary evidence. A
plaintiff is entitled to have a discovery as to two heads: first, to
enable him to obtain a decree, or to bring an action; or to ascer-
tain facts material to the merits of his case; either because he
cannot prove them, or in aid of proof, or to save expense; and
next he is entitled to a discovery of matters to substantiate his
proceedings and make them regular and effectual in this.Court.
Finch v. Finch, 2 Vex. 492; Brereton v. Gamul, 2 Atk. 241; Moodalay
v. Norton, 1 Bro. C. C. 469. But the disclosures, thus called for
must be pertinent and material to the plaintiff's case, and neces-
sary in order to enable him to recover; as where an executor was
required to say, whether be had a sufficiency of assets; and to
state an account, if he admits a sufficiency of assets to satisfy the
plaintiff 7s claim, he need not answer as to the account. Finch v.
Finch, 2 Ves. 492; Agar v. The Regents' Canal Co. Coop. Rep. 212.

But, although a man is allowed, voluntarily, to disclose any
thing against himself, however atrocious, he shall never be com-
pelled to criminate himself- or even to subject himself to a for
feiture; nemo tenetur seipsum accusare, is a maxim of the English
Code, which, with an evident reference to proceedings in Chancery,
has been engrafted into the fundamental law of the Republic. The
Twentieth Article of the Declaration of Rights provides, " that no
man ought to be compelled to give evidence against himself in a
Court of common law, or in any other Conrt, but in such cases as
have been usually practised in this State, or may hereafter be
directed by the Legislature." The sound sense of which is, that a
man shall not be obliged to discover what may subject him to a
penalty, nor what must only; Harrison v. Southcote, 1 Atk. 539; but
the boundaries are often very nice^ where a matter is near indicta-