FALSUS IN UNO DOCTRINE
falsus in uno doctrine (fal-s<<schwa>>s [orfawl-s<<schwa>>s] in yoo-noh). [fr. Latin falsus
in uno, falsus in omnibus “false in one thing, false in all”] The principle that if the jury believes
that a witness’s testimony on a material issue is intentionally deceitful, the jury may disregard all
of that witness’s testimony. [Cases: Trial 187, 210; Witnesses 317.C.J.S. Trial §§ 505, 571;
Witnesses § 570.]
“[T]here is an old maxim ‘falsus in uno, falsus in omnibus’ (false in one thing, false in all),
which is often much overemphasized by counsel, though it is recognized by many courts in their
charges to the jury. But this is only primitive psychology, and should be completely discarded.”
John H. Wigmore, A Students’ Textbook of the Law of Evidence 181 (1935).[Blacks Law 8th]