Mrs. Rose Anderson, Wife of Thomas Hay Marshall, Merchant in Perth v. Thomas Hay Marshall

Factual and Procedural Background

The Respondent (husband) initiated proceedings before the Scottish Commissaries seeking divorce from the Appellant (wife) on the ground of alleged adultery with two men, here anonymized as Witness A and Witness B. The Respondent’s proof established only circumstantial evidence—late-night meetings, physical proximity, disturbed clothing, encounters on a staircase, and affectionate letters—but no direct act of adultery. After the Respondent closed his proof, the Appellant moved to call Witness A and Witness B in her own defence. The Commissaries sustained the Respondent’s objection, ruling the witnesses incompetent as socii criminis. A petition for review was refused, and the Court of Session, on advocation, adhered to the Commissaries’ interlocutors. The Appellant then brought the present appeal to the House of Lords.

Legal Issues Presented

1. Whether alleged co-adulterers (socii criminis) are legally competent to testify for the defence in a Scottish action of divorce for adultery.

Arguments of the Parties

Appellant's Arguments

• Competency cannot be denied merely because the Respondent alleges they are socii criminis; guilt has not been proved.
• If a pursuer could bar any favourable testimony by naming potential witnesses as paramours, a defender would be unjustly deprived of essential evidence.
• Scottish law contains no authority absolutely excluding such witnesses; in analogous situations the pursuer has been allowed to call the alleged adulterer.

Respondent's Arguments

• The Appellant cannot invoke exculpatory evidence until the Respondent’s proof is complete and uncontradicted.
• Witness A and Witness B have a strong bias to exonerate themselves from civil damages and social infamy; their testimony would therefore lack credit.
• The admissibility of witnesses so heavily self-interested would undermine the strict evidentiary standards historically observed in Scottish divorce litigation.

Table of Precedents Cited

Court's Reasoning and Analysis

Judge Loughborough, delivering the opinion of the House, observed that Scottish rules of evidence, though historically strict, have progressively relaxed, mirroring broader common-law developments. He noted that in England Witness A and Witness B would unquestionably be competent witnesses, and that Scottish law had already departed from many older exclusions.

The Court emphasized consistency: in Nicholson Stewart the alleged paramour was held competent for the pursuer; logic and justice demanded the same rule e converso. The lower courts had erred by scrutinising the Respondent’s circumstantial proof and concluding it was so strong that no rebuttal should be heard; such a stance prevented the parties “most capable of clearing up” suspicious circumstances from testifying.

Examining the record, the House found the existing evidence “a heap of trumpery and trash” insufficient to foreclose further proof. Excluding Witness A and Witness B would therefore contravene both principle and practical justice.

Holding and Implications

REVERSED. The House of Lords set aside the interlocutors of the Commissaries and the Court of Session and remitted the cause with instructions to admit Witness A and Witness B as witnesses for the Appellant.

Implications: The decision affirms parity of treatment in Scottish divorce proceedings—if an alleged adulterer is competent for the pursuer, the same witness is competent for the defender. While the ruling liberalises evidentiary practice, it is confined to witness competency and does not establish a new substantive standard for proving adultery.