77 The modern foundation of the doctrine is the decision of the House of Lords in Maddison v Alderson (1883) 8 App Cas 467. The speech of Lord Selborne LC has become a starting point for later consideration. His Lordship's speech includes these observations (at 474-476):
The cases upon this subject (which are very numerous) have all, or nearly all, arisen under those words of the 4th section of the Statute of Frauds, which provide that "no action shall be brought to charge any person upon any contract or sale of lands, tenements, or hereditaments, or any interest in or concerning them, unless the agreement upon which such action shall be brought, or some memorandum or note thereof, shall be in writing, and signed by the party to be charged therewith, or some other person thereunto by him lawfully authorized."
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That equity has been stated by high authority to rest upon the principle of fraud: "Courts of Equity will not permit the statute to be made an instrument of fraud". By this it cannot be meant that equity will relieve against a public statute of general policy in cases admitted to fall within it; and I agree with an observation made by Lord Justice Cotton, in Britain v. Rossiter 11 Q.B.D. 130, that this summary way of stating the principle (however true it may be when properly understood) is not an adequate explanation, either of the precise grounds, or of the established limits, of the equitable doctrine of part performance.
In a suit founded on such part performance, the defendant is really "charged" upon the equities resulting from the acts done in execution of the contract, and not (within the meaning of the statute) upon the contract itself. If such equities were excluded, injustice of a kind which the statute cannot be thought to have had in contemplation would follow. Let the case be supposed of a parol contract to sell land, completely performed on both sides, as to everything except conveyance ; the whole purchase-money paid ; the purchaser put into possession ; expenditure by him (say in costly buildings) upon the property ; leases granted by him to tenants. The contract is not a nullity ; there is nothing in the statute to estop any Court which may have to exercise jurisdiction in the matter from inquiring into and taking notice of the truth of the facts. All the acts done must be referred to the actual contract, which is the measure and test of their legal and equitable character and consequences. If, therefore, in such a case a conveyance were refused, and an action of ejectment brought by the vendor or his heir against the purchase, nothing could be done towards ascertaining and adjusting the equitable rights and liabilities of the parties, without taking the contract into account. The matter has advanced beyond the stage of contract ; and the equities which arise out of the stage which it has reached cannot be administered unless the contract is regarded. The choice is between undoing what has been done (which is not always possible, or, if possible, just) and completing what has been left undone. The line may not always be capable of being so clearly drawn as in the case which I have supposed ; but it is not arbitrary or unreasonable to hold that when the statute says that no action is to be brought to charge any person upon a contract concerning land, it has in view the simple case in which he is charged upon the contract only, and not that in which there are equities resulting from res gestae subsequent to and arising out of the contract. So long as the connection of those res gestae with the alleged contract does not depend upon mere parol testimony, but is reasonably to be inferred from the res gestae themselves, justice seems to require some such limitation of the scope of the statute, which might otherwise interpose an obstacle even to the rectification of material errors, however clearly proved, in an executed conveyance, founded upon an unsigned agreement.
While extensively reviewing case law Lord Selborne said (at 478):
The doctrine, however, so established has been confined by judges of the greatest authority within limits intended to prevent a recurrence of the mischief which the statute was passed to suppress. The present case, resting entirely upon the parol evidence of one of the parties to the transaction, after the death of the other, forcibly illustrates the wisdom of the rule, which requires some evidentia rei to connect the alleged part performance with the alleged agreement. There is not otherwise enough in the situation in which the parties are found to raise questions which may not be solved without recourse to equity. It is not enough that an act done should be a condition of, or good consideration for, a contract, unless it is, as between the parties, such a part execution as to change their relative positions as to the subject-matter of the contract.
… it may be taken as now settled that part payment of purchase-money is not enough ; and judges of high authority have said the same even of payment in full: Clinan v. Cooke 1 Sch. & Lef. 40 ; Hughes v. Morris 2 D.M. & G. 356 ; Britain v. Rossiter 11 Q.B.D. 123. Some of the reasons which have been given for that conclusion are not satisfactory ; the best explanation of it seems to be, that the payment of money is an equivocal act, not (in itself), until the connection is established by parol testimony, indicative of a contract concerning land. I am not aware of any case in which the whole purchase-money has been paid without delivery of possession, nor is such a case at all likely to happen. All the authorities [show] that the acts relied upon as part performance must be unequivocally, and in their own nature, referable to some such agreement as that alleged : Cooth v. Jackson 6 Ves. 38 ; Frame v. Dawson 14 Ves. 386 ; Morphett v. Jones 1 Sw. 181. "The acknowledged possession" (said Sir T. Plumer in Morphett v. Jones 1 Sw. 181) "of a stranger in the land of another is not explicable, except on the supposition of an agreement, and has therefore constantly been received as evidence of an antecedent contract, and as sufficient to authorize an inquiry into the terms, the Court regarding what has been done as a consequence of contract or tenure."
"It is in general," said Sir James Wigram ( Dale v. Hamilton 5 Hare, 381) of the essence of such an act that the Court shall, by reason of the act itself, without knowing whether there was an agreement or not, find the parties unequivocally in a position different from that which, according to their legal rights, they would be in if there were no contract ….. But an act which though in truth done in pursuance of a contract, admits of explanation without supposing a contract, is not in general admitted to constitute an act of part performance taking the case out of the Statute of Frauds ; as for example, the payment of a sum of money alleged to be purchase-money. The fraud, in a moral point of view, may be as great in the one case as in the other, but in the latter cases the Court does not in general give relief": (see also Britain v. Rossiter 11 Q.B.D. at p.130, per Lord Justice Cotton.) The acts of part performance, exemplified in the long series of decided cases in which parol contracts concerning land have been enforced, have been (almost, if not quite, universally) relative to the possession, use, or tenure of the land. The law of equitable mortgage by deposit of title deeds depends upon the same principles.