Rule Text
If the witness is not testifying as an expert, the witness’s testimony in the form of opinions or inferences is limited to those opinions or inferences which are (a) rationally based on the perception of the witness and (b) helpful to a clear understanding of the witness’s testimony or the determination of a fact in issue.
Amendment history: (Added by SCO 364 effective August 1, 1979; amended by SCO 1522 effective October 15, 2003)
Committee Notes
Rule 701 follows the Federal Rule in departing from the impracticable common law prohibition of opinion testimony by lay witnesses. In the words of Judge Learned Hand: The truth is, as Mr. Wigmore has observed at length0.0.0.0that the exclusion of opinion evidence has been carried beyond reason in this country, and that it would be a large advance if courts were to admit it with freedom. The line between opinion and fact is at best only one of degree, and also depends solely upon practical considerations, as, for example, the saving of time and the mentality of the wit- ness….It is a good rule as nearly as one can, to reproduce the scene as it was, and so to correct the personal equations of the witnesses. But one must be careful not to miss the forest for the trees, as generally happens, unless much latitude is allowed. Central Railroad Co. v. Monahan, 11 F.2d 212, 213-214 (2d Cir. 1926). The rule retains the traditional objective of putting the trier of fact in possession of an accurate reproduction of the event. Limitation (a) is the familiar requirement of firsthand knowledge or observation. Limitation (b) is phrased in terms of requiring testimony to be helpful in resolving issues. Witnesses often find difficulty in expressing themselves in language which is not that of an opinion or conclusion. While the courts have made concessions in certain recurring situations, necessity as a standard for permitting opinions and conclusions has proved too elusive and too unadaptable to particular situations for purposes of satisfactory judicial administration. McCormick (2d ed.) § 11. Moreover, the practical impossibility of determining by rule what is a “fact,” demonstrated by a century of litigation of the question of what is a fact for purposes of pleading under the Field Code extends into evidence also. 7 Wigmore § 1919. The rule assumes that the natural characteristics of the adversary system will generally lead to an acceptable result, since the detailed account carries more conviction than the broad assertion, and a lawyer can be expected to display his witness to the best advantage. If he fails to do so, cross-examination and argument will point up the weakness. See, Ladd, Expert Testimony, 5 Vand. L. Rev. 414, 415-417 (1952). If, despite these considerations, attempts are made to introduce meaningless assertions which amount to little more than choosing up sides, exclusion for lack of helpfulness is called for by the rule.
