The Principle of Non Est Factum in Law: A Case Study of AOMO Limited v. Mr. Abiola Martins

Introduction

The doctrine of non est factum (Latin for "it is not my deed") is a legal defense in contract law that allows a party to avoid liability under a document they signed if they were fundamentally mistaken about its nature or contents, typically due to fraud, misrepresentation, or a significant error. This doctrine is significant in ensuring fairness by protecting parties from being bound by agreements they did not intend to enter. In Nigerian law, it is particularly relevant in disputes involving property transactions and contracts, where issues like fraud or illiteracy may arise. The case of AOMO Limited v. Mr. Abiola Martins (CA/L/63/2013), decided by the Court of Appeal of Nigeria, provides a case study for analyzing the application of non est factum in a property dispute involving a loan agreement and alleged assignment. This article explores the doctrine's historical development, practical application, and implications, using the case as a lens.

Historical Development

Origins in Roman Law

The roots of non est factum can be traced to Roman law, where the principle of error in negotio (mistake as to the nature of the transaction) allowed parties to void contracts entered under a fundamental misunderstanding. Roman jurisprudence, governed by maxims like pacta sunt servanda (agreements must be kept), balanced contractual enforcement with protections against fraud or mistake, as seen in the Digest of Justinian. This ensured that agreements lacking genuine consent could be set aside.

Development in English Common Law

In English common law, non est factum emerged as a defense in the 19th century to protect vulnerable parties, particularly those misled or illiterate. The landmark case of Foster v. Mackinnon (1869) LR 4 CP 704 established that a person who signs a document under a fundamental mistake about its nature (e.g., believing it to be a guarantee rather than a bill of exchange) could plead non est factum. The doctrine was refined in Saunders v. Anglia Building Society [1971] AC 1004 (also known as Gallie v. Lee), where the House of Lords clarified that the mistake must be fundamental and that the signer must not be negligent. The court emphasized that the doctrine applies narrowly to prevent abuse while upholding contractual certainty.

Application in Nigerian Law

In Nigeria, non est factum is recognized under common law principles and the Evidence Act, particularly in property and contract disputes. The Supreme Court case of Awosile v. Sotunbo (1992) 5 NWLR (Pt. 243) 514, cited in AOMO Limited v. Mr. Abiola Martins, underscored that a party relying on non est factum must provide evidence to prove the mistake or fraud, and failure to do so renders the defense inapplicable. Similarly, Ogun v. Asemah (2002) 3 NWLR (Pt. 753) 385 emphasized the need for specific pleadings and evidence of fraud or misrepresentation. Nigerian courts also consider the signer's literacy and diligence, aligning with Saunders v. Anglia Building Society.

How Non Est Factum Works in Practice

In Nigerian law, the doctrine of non est factum applies under specific conditions, derived from judicial precedents:

Fundamental Mistake: The signer must demonstrate a mistake about the document's nature or contents, not merely its terms. For example, signing a deed of sale believing it to be a loan agreement qualifies, as in Foster v. Mackinnon (supra).
Absence of Negligence: The signer must not have been negligent in failing to understand the document. Saunders v. Anglia Building Society (supra) established that negligence, such as failing to read a document, bars the defense.
Pleading and Evidence: The party must plead non est factum specifically in their Statement of Claim or Defence, with particulars of fraud, misrepresentation, or mistake, and support it with cogent evidence (Awosile v. Sotunbo, supra).
Third-Party Fraud: The mistake may result from fraud or misrepresentation by a third party, not necessarily the other contracting party, provided it induced the mistake (Lewis v. Clay (1897) 67 LJ QB 224).
Illiteracy Consideration: In Nigeria, illiteracy may strengthen a non est factum claim, but it must be pleaded and proven, as seen in Ogun v. Asemah (supra).

These conditions ensure that the doctrine is applied narrowly to balance contractual certainty with protection against unconscionable agreements.

Case Study – AOMO Limited v. Mr. Abiola Martins

Case Background

In AOMO Limited v. Mr. Abiola Martins (CA/L/63/2013), the respondent, Mr. Abiola Martins, initiated a lawsuit in the High Court of Lagos State (LD/2969/1997) against the appellant, AOMO Limited, concerning a property at Block 23, Flat 2, Ijeh Low Cost Housing Scheme, Lagos. The respondent, the property's allottee, borrowed N5,050.00 from the appellant, secured by the property, and repaid N3,000.00. He alleged that the appellant rejected his attempts to pay the remaining N2,050.00 and collected rents since 1989. The respondent sought, among other reliefs, a declaration that the agreements were loans simpliciter and an order setting aside any purported deed of sale, relying on non est factum to challenge any document transferring the property.

Key Legal Issue

The key issue was whether the respondent could rely on non est factum to void any document purporting to assign the property to the appellant, alleging fraud or mistake in the execution of such documents.

Court's Ruling

The High Court granted only the respondent's fifth relief, ordering the appellant to account for rents collected since 1988. The Court of Appeal, per Onyekachi Aja Otisi, JCA, upheld this decision. Regarding non est factum, the trial court found that the respondent pleaded the defense but failed to adduce evidence of fraud or mistake. The respondent admitted executing Exhibits A1 (mortgage agreement) and A2 (Deed of Mortgage by Assignment), undermining the claim of a fundamental mistake. The court, citing Awosile v. Sotunbo (1992) 5 NWLR (Pt. 243) 514, held that mere allegations of fraud in counsel's address could not substitute for evidence. Consequently, the non est factum defense was rejected, and reliefs relying on it (e.g., setting aside the deed) were struck out. The Court of Appeal found these submissions irrelevant on appeal, as there was no specific appeal against the trial court's ruling on non est factum.

Legal Implications of Non Est Factum in Litigation

Procedural Requirements

The case highlights the necessity of properly pleading non est factum with specific particulars of fraud or mistake, as required by Awosile v. Sotunbo (supra). Practitioners must ensure that claims are supported by evidence, as mere allegations in a Written Address are insufficient (Obasuyi v. Business Ventures Ltd. (2000) 5 NWLR (Pt. 658) 690). The failure to plead illiteracy or fraud specifically, as in this case, can doom the defense.

Contract Validity

Non est factum is critical in disputes involving alleged fraudulent or mistaken agreements, particularly in property transactions. The case illustrates that courts will uphold signed documents unless clear evidence of a fundamental mistake is provided. Legal practitioners must advise clients to verify documents before signing, especially in loan or mortgage agreements, to avoid being barred by negligence.

Judicial Power

The doctrine empowers courts to void documents that lack genuine consent, protecting vulnerable parties. However, AOMO Limited v. Mr. Abiola Martins demonstrates that courts will not lightly invoke non est factum without evidence, preserving contractual certainty. The judiciary's power to strike out unsupported claims, as seen here, reinforces the adversarial system's reliance on evidence.

Conclusion

The doctrine of non est factum remains a vital safeguard in Nigerian contract law, protecting parties from agreements entered under fundamental mistakes or fraud. However, its narrow application, as seen in AOMO Limited v. Mr. Abiola Martins, underscores the need for robust evidence and specific pleadings. Legal practitioners must ensure clients understand documents before signing and meticulously plead non est factum with supporting evidence to avoid dismissal. The case serves as a cautionary tale about the evidentiary burden required to succeed with this defense, emphasizing the balance between contractual freedom and fairness.