"it is a fundamental principle with the English Lawyers, that Parliament can do every thing, except making a Woman a Man, or a Man a Woman."

     Jean Louis de Lolme, The constitution of England, or An account of the English government; . . . 4th ed. corr. & enlarged, I.x ((London:  printed for G. Robinson . . . and J. Murray, 1784), 133a-134).  I haven't yet tracked this to an edition of the French original, but the French appears on p. 1043 of the 1992 Pléiade edition of Tocqueville as follows:  "C'est un principe fondamental pour les juristes anglais que le Parlement peut tout, sauf transformer une femme en homme et vice versa."  It appears in Appendix M of vol. 2 of the Reeve-Bowen-Bradley translation of Tocqueville I cite elsewhere in this blog ((New York:  Knopf, 1997), vol. 2, p. 355).
     The context is, of course, important here:

Owing to the above mentioned real difficulty in creating new Writs [or Briefs (Brevia)] on the one hand, and to the absolute necessity of such Writs in the Courts of Common Law on the other, many new species of claims and cases . . . are left unprovided for, and remain . . . like so many inaccessible spots, which the laws in being cannot reach. . . .     To remedy the above inconvenience, or rather in some degree to palliate it, law fictions have been resorted to, in the English law, by which Writs, being warped from their actual meaning, are made to extend to cases to which they in no shape belong.     Law fictions of the kind we mention were not unknown to the old Roman Jurisconsults; and as an instance of their ingenuity in that respect, may be mentioned that kind of action, in which a Daughter was called a Son (a). 

     (a) From the above instance it might be concluded that the Roman Jurisconsults were possessed of still greater power than the English Parliament; for", etc. (as above).