The Duchess of Kingstonʹs Case, the ruling of Lord Mansfield and duty of medical confidentiality in court

The aim of this article is to demonstrate that the ruling commonly cited as the original precedent11See for example: Dr C v. Complaints Assessment Committee [2006] N.Z.S.C. 48; D v. National Society for the Prevention of Cruelty to Children [1978] A.C. 171 at 237–240; Winterthur Swiss Insurance Company, The National Insurance & Guarantee Corporation Limited v. AG (Manchester) Limited (In Liquidation), Rowe Cohen (A Firm), Ashington Denton (A Firm) [2006] EWHC 839 at [66]; Three Rivers DC v. Bank of England (Disclosure) (No.4) [2005] 1 A.C. 610, [2004] UKHL 48, per Lord Carswell at 668 [86]; R. v. Derby Magistrates Court Ex p. B [1996] A.C. 487 at 504 (Lord Taylor of Gosforth CJ referring to ‘Sir Cecil Hawkins’ instead of Caesar Hawkins); Slavutych v. Baker, [1976] 1 S.C.R. 254; 55 D.LR. (3d) 224 (SCC) at 228 per Spence J; Watson v. McEwan (1904) 12 S.L.T. 599; Attorney General v. Briant (1846) 153 E.R. 808 at 179; Broad v. Pitt (1828) 172 Eng. Rep. 528 at 529; R. v. Gibbons (1823) 171 E.R. 1117; Upham v. You (1986) 11 C.P.C. (2d) 83, 73 N.S.R. (2d) 73, 176 A.P.R. 73 at [11]–[24] per Matthews JA speaking for the court; R. v. Young [1999] 46 N.S.W.L.R. 681 at 699, per Spigelman CJ speaking for the court; Watkins v. State of Queensland [2007] Q.C.A. 430; State of Western Australia v. PGM [2004] W.A.D.C. 95 at [39]. he doctrine that, at common law, medical practitionersʹ duty of confidentiality to their patients does not apply to court testimony,22For example: Anonymous, Attorney–Client Privilege. 98 Harv. L. Rev. 1501, 1502-03 (1985): Referring to John H. Wigmore, 8 Evidence in Trials at Common Law §2290, 543 & n.3 (M. McNaughton rev. ed. 1961), the author wrote: ‘Although the early utilitarian theory and the honour-based justification [for attorney–client communications] co-existed for a time, Lord Mansfield, in The Duchess of Kingstonʹs Case 20 How. St. Trials 355 (1776), explicitly rejected the honour-based justification because the same rationale might also justify the creation of a privilege for physician–patient relationships’ — at no stage did Lord Mansfield explicitly aver to the attorney–client privilege. For a different, though equally erroneous spin see: Thomas J. Reed, Evidentiary Failures: A Structural Theory of Evidence Applied to Hearsay Issues, 18 Am. J. Trial Advoc. 353, 385, fn 138 (1994): ‘In 1776, Lord Mansfield refused to recognise the Hippocratic Oath as the source of a common law confidential communications privilege between physician and patient. The Duchess of Kingstonʹs Trial, 20 How. St. Tr. 573 (1776)’. In fact, Lord Mansfield did not refer to the Hippocratic Oath; see also Angus H. Ferguson, The Lasting Legacy of a Bigamous Duchess: The Benchmark Precedent for Medical Confidentiality, 19 Soc. Hist. Med. 37–53 (2006). ot, in fact, establish any such theory. The ruling by Lord Mansfield was made in the context of cross-examination by the Crown of a medical witness in the course of the trial of the Duchess of Kingston (Duchess of Kingstonʹs Case (1776) 20 Howellʹs State Trials 355; [1775–1802] All ER Rep 623; [1776] 1 Leach 146), and this article will look briefly at: (1) the fascinating life of Elizabeth Chudleigh, the Dowager Duchess of Kingston, and the main events that led to her trial for bigamy; (2) the cross-examination of Caesar Hawkins and the different perceptions of the scope of confidentiality held by 18th century lawyers on the one hand and medical practitioners on the other; (3) Lord Mansfieldʹs ruling that witnesses cannot withhold from the court facts which the law considers to be in the public domain; (4) the subsequent wide interpretation, usually as judicial obiter dicta, of its final paragraph during the 19th century, including early jurisprudential responses to the principle of medical confidentiality; and (5) the influence of John Henry Wigmoreʹs opposition to patientsʹ evidentiary privilege at common law during the twentieth century.