We have seen (q) that, in order to make a valid contract, there must be free consent of the parties. Contracts induced by duress or undue influence are wanting in this element of validity: but in such contracts, as in the case of agreements induced by fraud, there is not the entire absence of consent which is characteristic of mistake (r). The party coerced or unduly influenced does really consent to the proposed agreement; only he would not have done so had he been a free agent (s). Contracts induced by duress or undue influence are therefore not void: but they are voidable at the option of the party whose consent was so procured (t). The common law did not go beyond avoiding contracts induced by duress, that is, actual force or threats of violence. And it is laid down that the duress must be of the person and not of property (as by wrongfully taking or withholding goods, or threatening to do so); and that if actual force were not used, there must be the fear of losing life or limb, or of unlawful imprisonment. Thus battery was duress, but not the mere threat of battery (u). And the duress must have been used to the party to the contract himself or to his wife, child or parent (x). In equity, however, a far wider jurisdiction was assumed to set aside contracts made without free consent; and it was adjudged to be sufficient to avoid a contract or a conveyance if there were such constraint of the will of the party making it that his consent (y) thereto were not free, although the constraint did not amount to duress at common law (z). And this doctrine of equity is by no means confined to the inducement of consent by outward force or fear; it extends to every case in which such influence is exerted by one party to a contract or conveyance over the mind of another that the other does not in fact consent thereto of his own free will (a). The question to be determined in each case is whether the party, who alleges that he was unduly influenced, agreed to the contract or conveyance made as a free agent exercising his own untrammelled volition; and if he did not, he may avoid the transaction (a).

Contracts induced by duress or undue influence are voidable.

(m) Bank of England v. Vagliano, 1891, A. C. 107, 116.

(n) Jones v. Ryde, 5 Taunt. 488; Wilkinson v. Johnston, 3 B. & C. 428, 434; Gurney v. Womersley, 4 E. & B. 133. As to the recovery of money paid under a mistake of fact, see Kelly v. Solan, 9 M. & W. 54; He Bodega Co., Ld., 1904, 1 Ch. 276.

(o) Cocks v. Masterman, 9 B. & C. 902; London and River Plate Bank v. Bank of Liverpool, 1896, 1 Q. B. 7.

(p) Starkey v. Bank of England, 1903, A. C. 114.

(q) Above, p. 2.

(r) Above, pp. 666, 674.

(s) Cf. above, p. 674.

Duress at common law.

Equitable doctrine of undue influence.

(t) Bract, fo. 100b (Sec. 13), 396b (Sec. 3); 2 Inst. 4 82; Whelpdale's ease, 5 Rep. 119, and cases cited below. It may be noted that, in the case of the marriage contract, which is peculiar and of which the initial validity or invalidity depends partly on considerations foreign to the common law, a consent induced by fraud, force or fear, may be treated as being no consent at all; see Fulwood's ease, Cro. Car. 488, 493 : Harford v. Morris, 2 Hagg. Cons. 423, 425, 436; Field's Marriage, 2 H. L. C. 48, 68-62; Scott v. Sebright, 12 P. D. 21; Cooper v. Craw, 1891, P. 369, 376; Ford v. Stier, 1896, P. 1 ; 1 Black.

Coram. 433 - 436; Bishop on Marriage and Divorce (Chicago, 1891), vol. i. Sec. 54S ; Moss v. Moss, 1897, P. 263, 271 sq.

(u) 2 Inst. 483; Bac. Abr. Duress (A); 1 Black. Coram. 130, 131, 136; Skeate v. Beale, 11 A. & E. 983, 990.

(x) Bac. Abr. Duress (B).

(y), See above, p. 667 and n. (e).

(z) A.-G. v. Sothon, 2 Vern. 497; Huguenin v. Baseley, 14

Ves. 273, 294; Peel v. ------, 16

Ves. 157, 159; and see Chesterfield v. Janssen, 2 Ves. sen. 125, 155 - 157, where this jurisdiction is alluded to as a branch of the equitable jurisdiction to relieve against fraud.

The cases, in which a contract or conveyance may be avoided for undue influence, are usually divided into two classes. The first is where the alleged ground of avoidance simply is that the one party did in fact actively exercise such influence over the other's mind that he was not a free agent, and it is not asserted that the one stood in any confidential relation to the other (b). The second is where it is claimed that undue influence should be implied from the fact that there was a confidential relation between the parties, which invested the one with a peculiar authority over the other, or imposed on him a special duty of advising the other (c). In both classes the question to be determined is the same; was such influence exerted as to interfere with the freedom of the other's will? But they differ with respect to the burthen of proof. This lies, in the first class, entirely on the party who seeks to set the transaction aside (d). In the second, the plaintiff must show that the alleged confidential relation existed: but when this has been established, it is presumed, until the contrary be shown, that advantage was taken of it; and the obligation then lies on the defendant of proving that the plaintiff was not unduly influenced and that his consent was quite free (e). This class of cases is exemplified in the relation of solicitor and client (f), parent, or other person in loco parentis and child {g), guardian and ward (h), confessor or other spiritual adviser or religious superior and penitent or disciple (i), and doctor and patient (k). But the doctrine is not confined to any particular set of confidential relations. If any relation be established between the parties, of which the natural consequence would be that the one would come under the other's influence, the same rule applies, and the onus is on the party occupying the position of influence to prove that the other gave his unbiassed consent (l). It is enough, for instance, that one has taken upon himself or come to be the other's confidential adviser in business matters or the manager of his property (m). But there is no presumption of undue influence on the part of a husband in transactions between himself and his wife(n). The equitable rules as to the avoidance of transactions induced by undue influence apply, not only to contracts and conveyances for value, but also (and of course more readily) to voluntary conveyances, settlements and gifts, when made inter vivos (o). But the presumption of undue influence from the establishment of a confidential relation between the parties has no application in the case of gifts by will; and to upset such a gift, it must be shown, not merely that the legatee solicited or put forward claims to the testator's bounty, but that the testator's volition to the contrary was overborne by the legatee's influence (p).