Supposing the agreement and its breach to be prima, facie capable of proof against the defendant, he may, by way of defence to the action, show, either that the agreement was originally invalid, or that it has since its execution ceased to be binding, or that satisfaction has been made for its breach: or that it was to be conditional upon some event which has not occurred (o).

Grounds of defence to action on contract duly executed.

For instance, he may show that, at the time of the execution of the contract, he was under some personal incapacity to contract (p) ; or was under duress (q) ; or was fraudulently induced to enter into it (r) ; in which case it is voidable at his election (s) ; or that it contains provisions against public policy (t) ; or was entered into for or with reference to some unlawful purpose (u). But a contract legal in its inception cannot be rendered illegal by matter ex post facto (x) ; although it may be avoided by a collateral and contemporary illegal agreement (y).

Original invalidity of contract;

(o) Pym v. Campbell, (1856) 6 E. & B. 370 ; 25 L. J. Q. B. 277; Clever v. Kirkman, (1876) 33 L. T. 672; Puttie v. Hornibrook, sup. ; and cf. Krell v. Henry, 1903, 2 K. B. 740 ; 72 L. J. K. B. 791; Blakeley v. Midler, (1903) 88 L. T. 90 ; Clark v. Lindsay, (1903) 88 L. T. 198; Chandler v. Webster, 1904, 1 K. B. 493; 73 L. J. K. B. 401; cases where rooms were let for purpose of viewing coronation procession which was abandoned ; and Civil Service Co-op. Soc. v. General Steam Nav. Co., 1903, 2 K. B. 756 ; 72 L. J. K. B. 933 ; Herne Bay Steamboat Co. v. Hutton, 1903, 2 K. B. 683 ; 72 L. J. K. B. 879 ; Elliott v. Crutchley, 1904, 1 K. B. 5G5 ; 73 L. J. K. B. 406 ; cases where ships were chartered for postponed naval review.

(p) Sup. Ch. I. ; see as to intoxication, Gore v. Gibson, (1845) 13 M. & W. 623 ; 14 L. J. Ex. 151 ; Motion v. Camroux, (1819) 4 Ex. 17; Matthews v. Baxter, (1873) L. R. 8 Ex. 132 ; 42 L. J. Ex. 73 ; Pollock on Contract, 7th ed. 93 et seq.

(q) Bac Abr. tit. "Duress ; "

Addison on Contract, 10th ed. 121.

(r) See sup. p. 101 et seq.; and Pasley v. Freeman, and notes thereto, 2 Sm. L. C. 11th ed. p. 67; actual fraud in the agent, in respect to matters within the scope of his authority is the same as fraud in the principal, unless the agent is acting for his own purposes, ib. p. 99 etseq.

(s) White v. Garden, (1851) 10 C. B. 919; 20 L. J. C. P. 166.

(t) Vansittart v. V., (1858) 4 K. & Jo. 62; 2 De G. & J. 249 ; 27 L. J. Ch. 222, 289 ; Ayerst v. Jenkins, (1873) 16 Eq. 275 ; 42 L. J. Ch. 690 ; and judgment of Ld. Sel-horne; Humphrys v. Polnk, 1901, 2 K. B. 385 ; 70 L. J. K. B. 752 ; and see Pollock on Contract, 312 et seq.

(a) Bartlett v. Vinor, (1692) Carth. 251 ; Langton v. Hughes, (1813) 1 M. & S. at p. 596 ; I)e Begnis v. Armistead, (1833) 10 Bing. 107; Gas Light Co. v. Turner, (1839) 5 Bing. N. C. 666; 6 ib. 324 ; Ritchie v. Smith, (18 18) 6 C. B. 462 ; 18 L. J. C. P. 9 ; Fisher v.Bridges, (1854) 3E. & B. 642; 23 L. J. Q. B. 276 ; and see Ewing v. Osbalduton, (1837) 2 M. & C. 53; 6

So, admitting its original validity, he may show that it has been since avoided by having, without his concurrence, been altered by the plaintiff in a material part (z); or by a waiver in writing duly signed by the plaintiff (a), before the breach which is relied on in the action. Where a parol has been substituted for a written agreement, which in order to be valid must be in writing, no action will lie on the substituted agreement (b); and verbal waiver of such a written agreement is no defence at Law (c). For example, where there was a written contract for the sale of goods, to be delivered within a specified period, and there was a subsequent parol extension of the time for delivery, it was held that the subsequent parol agreement could not operate either as a rescission of the written contract, or as creating a new contract; and that the vendor might revert to his original position, and sue on the written contract (d). But even at Law a distinction has been drawn between an alteration of the contract by enlarging the time, or the substitution of a new parol contract, and a mere dispensation of its performance at the time stipulated, or the substitution of a new mode of performance (?) ; and it is not clear that a parol waiver would not be admissible as a defence under the Judicature Act (f).

Or subsequent waiver; which, if verbal, is no defence at Law, where the agreement is required to be in writing.

L. J. N. S. Ch. 161; and note, anything to which a statute attaches a penalty is unlawful, though not expressly prohibited, S. C.; and see Duke of Roxburghe v. Ramsay, (1850) 7 Bell's Ap. C. 248 ; Applet on v. Campbell, (1826) 2 C. & P. 347 ; M'Gregor v. Dover R. Co., (1853) 17 Jur. 21 ; 22 L. J. Q. B. 69 ; Tallis v. T., (1853) 1 E. & B. 391; 22 L. J. Q. B. 185 ; Taylor v. Crowland Gas Co., (1854) 10 Ex. 293 ; 23 L. J. Ex. 254 ; Jones v. Orchard, (1855) 3 C. L. R. 1275 ; 24 L. J. C. P. 229 ; sup. 277; Addison on Contract, 10th ed. 83 etseq.

(x) Fraser v. Hill, (1853) ] Macq. 392 ; Armstrong v. A., (1834) 3 M. & K. 64 ; 3 L. J. N. S. Ch. 101; Pollock on Contract, 7th ed. 376, 377.

(y) Armstrong v. Lewis, (1834) 2 C. & M. 298 ; ef. Cowan v. Milboum, (1867) L. R. 2 Ex. 230 ; 36 L. J. Ex. 124 ; but an estate conveyed cannot be divested by the existence of an unlawful purpose on the part of the grantee, and fraudulent misrepresentation by him: Feret v. Hill, (1854) 15 C. B. 207; 23 L. J. C. P. 186; and see Ayerst v. Jenkins, (1873) 16

Eq. 275 ; 42 L. J. Ch. 690. (a) Sup. p. 261.

(a) See Goss v. lord Nugent, (1833) 2 N. & M. 28 ; 2 L. J. N. S. K. B. 127 ; Harvey v. Grabham, (1836) 6 N. & M. 754, 762 ; 5 L. J. N. S. K. B. 235 ; Sanderson v. Graves, (1875) L. R. 10 Ex. 234; 44 L. J. Ex. 210.

(b) Steady. Dawber, (1839) 10 A. & E. 57 ; Goss v. Lord Nugent, (1833) 5 B. & Ad. 58, 66; 2 L. J. N. S. K. B. 127 ; Plevins v. Downing, (1876)

1 C. P. D. 220 ; 45 L. J. C. P. 695

(c) See Noble v. Ward, (1867) L. R.

2 Ex. 135 ; 36 L. J. Ex. 91; Moore v. Campbell, (1854) 10 Ex. 323; 23 L. J. Ex. 310 ; Goss v. Lord Nugent, and Stead v. Dawber, sup. ; Marshall v. Lynn, (1840) 6 M. & W. 109 ; but see Clark v. Upton, (1828) 3 Man. & R. 89, where the purchaser's action was held to be barred by his own application to the vendor to rescind the contract, and which the latter had, substantially, though not in terms, complied with ; see, too, Nash v. Armstrong, (1861) 10 C. B. N. S. 259; 30 L. J. C. P. 286 : Sug. 14th ed. 164, 165.

Where a right of action has actually arisen, this can be discharged only by a release under seal, or by the acceptance of something by way of satisfaction (g). Where the contract is under seal, there can be no parol discharge before breach (h).

So the defendant, admitting the agreement and its breach, may show that the plaintiff has executed a release under seal; or has accepted something in satisfaction of the breach (i); or has already recovered damages in an action upon the agreement (k) ; or that the action is barred by the Statute of Limitations.

Or release; or satisfaction.

So, on the principle of the maxim lex non cogit ad impossibilia, where a lessor covenanted that neither he nor his assigns would, during the term, permit any building to be erected on land fronting the demised property, and this land was afterwards compulsorily taken by a railway company who erected a station thereon, the covenantor was held to be discharged by the Act from his obligations under the covenant (/). The remedy of the covenantee in such a case is compensation under s. 68 of the L. C. C. Act, 1845 (m).

Or the impossibility of performing it.

(d) Noble v. Ward, (1867) L. R. 2 Ex. 135; 36 L. J. Ex. 91.

(e) Ogle v. Earl Vane, (1868) L. R. 3 Q. B. 272 ; 37 L. J. Q. B. 77 ; Hickman v. Haynes, (1875) L. R. 10 C. P. 598; 44 L. J. C. P. 358; Leather Cloth Co. v. Hieronimus, (1875) L. R. 10 Q. B. 140 ; 44 L. J. Q. B. 54 ; Plevins v. Downing, (1876) 1 C. P. D. 220 ; 45 L. J. C. P. 695.

(f) See Addison, 10th ed. p. 156 et teq. ; also Vezey v. Rashleigh, 1904,

1 Ch. 631; 73 L.J. Ch. 422.

(g) Willoughby v. Backhouse, (1824)

2 B. & C. 821, 824; see Baylis v. Usher, (1830) 7 Bing. 153.

(h) Spence v. Hcaley, (1853) 8 Ex. 668; 22 L. J. Ex. 249; Mayor of Berwick v. Oswald, (1853) 1 E. & B. 295 ; 22 L. J. Q. B. 129.

(e) Willoughby v. Backhouse and Baylis v. Usher, sup.

(k) See Orme v. Broughton (1834) 10 Bing. at p. 538.