The second type of case which reference has been made - a contract to discharge an obligation of the promisee - has been held in England enforceable only by the promisee;40 and the law of Canada is the same.41 This rule does not operate as unjustly as the rule in the other type of cases, for here both the promisee and the third party have an adequate remedy. The object of such a contract must always be primarily and generally solely to secure an advantage to the promisee. He wishes to be relieved from liability, and he exacts a promise to pay the third person only because that is a way of relieving himself. If the promisor breaks his promise the promisee suffers material damage, namely, the amount of the liability which should have been discharged and which in fact still exists, and according to ordinary rules of contract the promisor is liable for this damage.42 The third person, moreover, can sue his original debtor. This was the right for which he bargained. If he is given also a direct right against the promisor, the latter is subjected to a double right of action on a single promise, and the creditor is allowed to take advantage of a promise for which he did not furnish the consideration and in which the contracting parties had their own advantage, not his, in mind.
394 De G. 4 3. 517; Ames, Gas. Trusts, 2d ed., 39. See also M'Fad-den v. Jenkyns, 1 Phillips, 153; Ames, Cas. Trusts, 47. In Walford v. Lea Affreteurs Remus Societe Anonyme, (1918) 2 K. B. 498, a clause in a charter party provided that a commission should be paid by the owners to the broken in the transaction. The charterers were held entitled to sue upon this promise as trustees for the brokers.
40Crow v. Rogers, 1 Strange, 592;
Price v. Easton, 4 B. & Ad. 433; Re Empress Engineering Co., 16 Ch. D. 125,129; Bonner v. Tottenham Society,  1 Q. B. 161. But see Gregory v. Williams, 3 Mer. 582.
41 Henderson v. Killey, 17 Ont. App. 456; s. c sub nam. Osborne v. Henderson, 18 Can. S. C. 698; Robertson v. Lonsdale, 21 Ont. 600; Canadian Mo-line Plow Co. v. Troa, 39 D. L. R. 581; Cochrane v. Caie, 3 Piigaley (N. Brunswick), 224.