Abstract
In this paper, I aim to explicate the distinction between ‘unconditional relevance’ and ‘conditional relevance’ as those terms and related concepts are applied in the context of admissibility determinations in modern trials. I take the U.S. Federal Rules of Evidence to be my model in analyzing these concepts, though on my view any reasonable approach to legal evidence will have to distinguish between these concepts and make appropriate provisions for their separate treatment. I begin by explaining how the Federal Rules define and apply the concepts of relevance and conditional relevance, and I present an influential argument due to Vaughn Ball that threatens to undermine the distinction between the two concepts. I then argue that Ball's argument fails and I diagnose that failure. However, building on some insights from a variety of evidence scholars, I argue that the approach to conditional relevance adopted by the Federal Rules is crucially flawed for reasons entirely independent of the ones raised by Ball's argument. I identify the main constraints that, on my view, any reasonable approach to conditional admissibility must obey, and I argue for a specific proposal that obeys those constraints. On my positive view, two pieces of evidence should be admitted under a Conditional Admissibility Principle only when each piece of evidence would survive ordinary admissibility scrutiny, conditional on the admission of the other one. I conclude by considering the question of whether it should also be necessary for the two pieces of evidence to survive admissibility scrutiny together, as an ‘evidential package’; I argue that, though the issue may arise infrequently in practice, there is good reason to impose this additional requirement.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
See Fed. R. Evid. 402 (‘Irrelevant evidence is not admissible’.).
See id. (‘Relevant evidence is admissible unless any of the following provides otherwise: the United States Constitution; a federal statute; these rules; or other rules prescribed by the Supreme Court’.)
Though Rule 401 purports to give only a sufficient condition for relevance (‘Evidence is relevant if...’) (emphasis added), it is uniformly interpreted to provide a necessary and sufficient condition for relevance; in accordance with that standard approach, I will treat Rule 401 as though the ‘if’ were an ‘if and only if’.
Fed. R. Evid. 401.
One way for this to happen is if A has a more or less significant tendency to confirm or disconfirm some particular fact of consequence than B does. Another way for this to happen is if A has a tendency to confirm or disconfirm a fact that is of more or less significant consequence than B does.
Fed. R. Evid. 403 (‘The court may exclude relevant evidence if its probative value is substantially outweighed by a danger of one or more of the following: unfair prejudice, confusing the issues, misleading the jury, wasting time, or needlessly presenting cumulative evidence’.).
See Advisory Committee’s note on Rule 104(b). Of course, the heated argument might also be relevant to establishing other facts of consequence, such as identity, motive, etc.
See id.
See, e.g., Ronald J. Allen, 'The Myth of Conditional Relevancy', 25. loy. l. a. l. rev. 871 (1992).
See, e.g., John Henry Wigmore, A Treatise on the System of Evidence in Trials at Common Law §2570 (3d ed. 1981): ‘...so far as the matter in question is one upon which men in general have a common fund of experience and knowledge, through data notoriously accepted by all, the analogy of judicial notice obtains to some extent, and the jury are allowed to resort to this information in making up their minds’.
See Edmund Morgan, Basic Problems of Evidence 45–46 (1962).
Nor does this evidence, all by itself, appear to have any tendency to change the probability of any other fact of consequence to the breach of contract claim.
Fed. R. Evid. 104(b).
There is a possible complication here, to which I alluded above, in cases where a logically relevant piece of evidence is completely ‘undercut’ by subsequent evidence—say, where the evidential impact of the heated exchange between the defendant and the victim is completely neutralized by uncontroverted proof that the exchange took place as a scripted component of a rehearsal for a play. It may be natural to characterize such cases as examples of logically relevant evidence becoming irrelevant; however, this complication will not impact my aims in this paper, in large part because the undercutting evidence at issue would typically be introduced after the logically relevant evidence and hence would not interfere with its admissibility. But, regardless of whether it is possible for logically relevant evidence to become irrelevant, it is certainly impossible for irrelevant evidence to become logically relevant.
It is also worth nothing that, for nearly any E and F, there is some proposition relative to which E is conditionally relevant to F. For example, the fact that Juan’s favorite color is orange is conditionally relevant to whether Oswald killed Kennedy, conditional on the truth of the material conditional proposition that if Juan’s favorite color is orange then Oswald killed Kennedy.
There is a subtlety here about whether it is the proposition itself or the evidence of the proposition that should be properly regarded as the predicate. I will return to this issue in Section 7.
Vaughn C. Ball, 'The Myth of Conditional Relevancy', 14 ga. l. rev. 435 (1980).
Id. at 454.
See id. at 447–451.
Id. at 450–451.
Id. at 451.
Id. at 453.
Id. at 458.
Id. at 469.
See, e.g., Wigmore, Evidence §14.1 (Peter Tillers rev. 1983); 21A Fed. Prac. & Proc. Evid. §5052.4 (2d ed.) (‘Readers who have understood Professor Ball’s argument will understand that dilemma supposed to arise in this case—both facts are relevant but neither can be proved unless the other is proved first—does not arise under the Evidence Rules’.); Christopher B. Mueller & Laird C. Kirkpatrick, Evidence §1.13, at 48 & n.7 (citing Ball and concluding that ‘the concept of conditional relevancy seems...intuitively true but logically false’); Craig R. Callen, ‘Rationality and Relevancy: Conditional Relevancy and Constrained Resources’, 2003 mich. st. l. rev. 1243, 1247–1249 (2003); Douglas Walton, ‘Argumentation Schemes: The Basis of Conditional Relevance’, 2003 mich. st. l. rev. 1205, 1232 (2003) (‘Another problem shown by Ball is that conditional relevance is hard to define, in precise operational terms, as an exact logical concept’.)
Allen, supra note 9.
See id. at 871–872, 884. See also R. Allen & R. Kuhns, An Analytical Approach to Evidence 165–168 (1989) (endorsing Ball’s ‘brilliant’ article).
Id. at 872.
Id.
Id. at 879.
Allen, supra note 9, at 877.
‘The determinations [of relevance and conditional relevance] are analytically identical, and thus the standard applicable to them should be the same’. Id. at 883.
‘‘[C]onditional relevancy’ is simply the label applied to a case that the trial judge finds insufficient to go to the jury and ‘relevancy’ is the label applied to a case that the judge finds sufficient to go to the jury. We need no further proof of their identical nature’. Id. at 880.
Of course, it is also (negatively) relevant conditional on the defendant being left-handed.
See Sara M. Scharoun & Pamela J. Bryden, ‘Hand preference, performance abilities, and hand selection in children’, 5 Frontiers in Psychology 82 (2014).
Friedman considers a case that is like my handedness example, though he largely dismisses its significance because of his emphasis on conditional probative value over conditional relevance. See Richard D. Friedman, ‘Conditional Probative Value: Neoclassicism without Myth’, 93 Mich. L. Rev. 439, 443–444 (1994). Ball also considers a case with a similar structure, but he too dismisses it on the grounds that the example involves two offsetting evidential effects, one confirmatory and one disconfirmatory. See Ball, supra note 17, n. 38 at 466–469.
These examples are closely related to violations of Hempel’s ‘Special Consequence Condition’—i.e., the thesis that if E confirms H1, and H1 entails H2, then E confirms H2 as well. See Carl Hempel, Aspects of Scientific Explanation (1965). In the lottery case, the information that the winning ticket is higher than 10 (somewhat) confirms the hypothesis that my ticket and the winning ticket are both (say) #82, which entails that I’ve won, but the information that the winning ticket is higher than 10 fails to confirm the hypothesis that I’ve won. Similarly, in the handedness case, the information that the killer is right-handed confirms the hypothesis that the killer and the defendant are both right-handed, which entails that the handedness of the killer and the defendant match, but the information that the killer is right-handed fails to confirm that the hypothesis that the handedness of the killer and the defendant match. For a detailed discussion of Hempel’s Special Consequence Condition, see Matthew Kotzen, ‘Dragging and Confirming’, 121 The Philosophical Review, 55 (2012).
The forensic evidence is also conditionally (negatively) relevant, conditional on the introduction of evidence sufficient to support a finding that the defendant is left-handed. But these two facts do not entail that the forensic evidence is unconditionally relevant to the question of whether the defendant is the killer.
Allen, supra note 9, at 880.
Allen, supra note 9, at 881–883.
See, e.g., Friedman, supra note 36, at 448–451; Dale A. Nance, ‘Conditional Relevance Reinterpreted', 70 B.U.L. Rev. 447, 451 (1990) (‘...the trier [of fact] must make a finding, by the appropriate standard of proof, only as to the ultimate propositions in the case, not as to intermediate evidentiary propositions contained within inferential chains’.) (emphasis in original); David S. Schwartz, ‘A Foundation Theory of Evidence', 100 Geo. L. J. 95, 118 (2011).
Huddleston v. United States, 485 U.S. 681, 690 (1988) (‘In determining whether [the proponent] has introduced sufficient evidence to meet Rule 104(b), the trial court ...simply examines all the evidence in the case and decides whether the jury could reasonably find the conditional fact ...by a preponderance of the evidence’.).
Schwartz, supra note 41, at 118 (‘To impose the FRE 104(b) requirement of the higher, ‘evidence to support a finding’ standard could theoretically be done as to any offer of evidence, making its application a random and arbitrary choice by the judge; and a consistent application of FRE 104(b) would swallow FRE 401 whole’.).
See, e.g., Friedman, supra note 36, at 448–451. Friedman gives two examples where this might arise: 1) A situation where the proffered evidence is relevant conditional on two (or more) different predicates, and where there is evidence sufficient to support a finding that at least one of the predicates is true, but where there is not evidence sufficient to support a finding that any particular predicate is true. 2) A situation where a proponent without the burden of persuasion endeavors to introduce conditionally relevant evidence, conditional on a predicate for which there is some evidence but not evidence sufficient to support a finding by a preponderance. I will add a third: A situation in which the conditionally relevant evidence and the evidence for the predicate are not the only evidence in favor of the fact of consequence (regardless of whether the proponent has the burden of persuasion or not). In such a situation, the conditionally relevant evidence might be significantly probative as long as there is some evidence for the predicate, even if the evidence for the predicate is not sufficient to support a finding of its existence by a preponderance. And since (we are supposing) there is other evidence in favor of the same fact of consequence, there is no reason that a verdict must be directed against the proponent, even if he has the burden of persuasion. Indeed, to exclude conditionally relevant evidence when there is some evidence in favor of the predicate, on the grounds that the evidence for the predicate is not sufficient to support a finding of its existence by a preponderance, is to introduce an unmotivated asymmetry between conditionally relevant evidence and unconditionally relevant evidence. Even only mildly probative unconditionally relevant evidence can be admitted under Rule 403 as long as its probative value is not substantially outweighed by a danger of unfair prejudice, etc., without the need for the court to reach a threshold finding that there is evidence sufficient to support any particular factual proposition. To categorically exclude conditionally relevant evidence in a situation where the evidence in favor of the predicate renders the conditionally relevant evidence relevant, simply because the evidence in favor of the predicate is not sufficient to support a finding of its existence, is to introduce a completely unmotivated asymmetry between the treatment of unconditionally relevant evidence and conditionally relevant evidence.
Note too that there are other provisions of the Federal Rules that similarly adopt a permissive standard for admissibility, in the interest of preserving the jury’s factfinding role. See, e.g., Fed. R. Evid. 403. But see Fed. R. Evid. 412(b)(2).
Friedman, supra note 36, at 454–455.
On the standard approach to conditional admissibility under the FRE, the court must first make the preliminary determination that a particular piece of evidence is conditionally relevant, conditional on the truth of the predicate proposition, and then must make the separate determination that sufficient proof has been introduced to support the finding that the predicate proposition is true. By focusing instead on the relationship between the conditionally probative evidence and the predicate evidence, the issue of whether sufficient proof has been introduced to support the finding that the predicate proposition is true is removed from the analysis. Of course, the issue of whether the conditionally probative evidence has sufficient conditional probative value to be admitted is still a preliminary question to be determined by the court. But the reason that the jury’s factfinding role is less restricted under Friedman’s approach is that the conditionally probative evidence is admitted subject only to the introduction of the predicate evidence; no preliminary determination by the court is required is order to settle whether that predicate evidence is sufficient to support any particular finding by the jury.
Friedman, supra note 36; Nance, supra note 41, at 473.
I have simplified and modified the notation here to be more consistent with the rest of this paper.
Id. at 456–457.
It is controversial how to measure ‘amount' of confirmation, which is closely related to degree of probative value. See, e.g., Branden Fitelson, ‘The Plurality of Bayesian Measures of Confirmation and the Problem of Measure Sensitivity’, 66 Philosophy of Science Supplement S362 (1999).
Friedman, supra note 36, at 445.
Id. at 445 n. 23.
Id. at 455.
Id. at 477.
Id. at 445.
Id. at 477.
See id. at 445 n. 23: ‘Those cases to which the conditional relevance label would apply—because the proffered evidence would be irrelevant without proof of the predicate proposition...—would also be cases of conditional probative value....’
Fed. R. Evid. 403 (‘The court may exclude relevant evidence if its probative value is substantially outweighed by a danger of one or more of the following: unfair prejudice, confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting cumulative evidence’.)
Similar remarks will apply to any code of evidence which takes relevance to be a necessary condition for admissibility.
A preliminary issue that would arise without Rule 104(b) is whether the definition of ‘relevance’ in Rule 401 takes the evidence already in the record into consideration. In other words, supposing that A has already been admitted into evidence, the question would arise as to whether B’s ‘tendency to make a fact [of consequence] more or less probable than it would be without’ B is evaluated ‘logically’ or relative to the total body of admitted evidence, including A. As I indicated in Section 1, I have been using the term ‘relevance’ in the latter sense; on my usage, B counts as ‘relevant’ evidence if it tends to make a fact of consequence more or less probable, on the assumption of all of the other evidence that is already in the record. Thus, on my usage, Rule 104(b) is not required in Situation 1 in order to permit the introduction of B once A has already been introduced, since A’s introduction renders B relevant under Rule 401 and hence potentially admissible. Still, Rule 104(b) resolves any potential ambiguity here; with Rule 104(b), it is obvious that logical relevance is not required in order to satisfy Rule 401’s definition of ‘relevance’.
Fed. R. Evid. 611(a). See also Huddleston v. United States, 485 U.S. 681, 690 (1988) (‘The trial court has traditionally exercised the broadest sort of discretion in controlling the order of proof at trial, and we see nothing in the Rules of Evidence that would change this practice’.).
Thanks to Andy Hessick for helpful discussion here.
See, e.g., Schwartz, supra note 41, at 108; David A. Sklansky, Evidence: Cases, Commentary, and Problems, 620 (2003) (‘[A]uthentication is best understood as a specific application of a more [general] principle of evidence law: conditional relevance’.); 1 Jack B. Weinstein & Margaret A. Berger, Weinstein’s Federal Evidence §104.30[3] (2021) (‘[Rule 901(a)’s] requirement of authentication or identification is the paradigm of a preliminary question under Rule 104(b)’.).
For example, many of the same issues as addressed above involving imposition on the jury’s factfinding role arise for Rule 901 as for Rule 104(b). In particular, even if evidence sufficient to support a finding that an exhibit is genuine has not been introduced, a reasonable jury still may accord the exhibit nontrivial weight, as long as some evidence of its genuineness has been introduced. If the Two-Part Test were generalized to the context of authentication, the question of admissibility would come to the questions (a) whether the exhibit is relevant and survives 403 analysis, on the assumption of the authentication evidence; and (b) whether the authentication evidence is relevant and survives 403 analysis, on the assumption of the exhibit. This approach would enjoy many of the advantages of the Two-Part Test in the context of conditional proffers; for example, it would help to address a version of the Prejudicial Predicate Problem that arises when the authentication evidence itself presents a danger of unfair prejudice.
Thanks to Branden Fitelson for assistance in using the Mathematica PrSAT package to formulate this case precisely.
See, e.g., Ballou v. Henri Studios, Inc., 656 F.2d 1147 (5th Cir. 1981).
This concern was also a central focus of the 1973 Advisory Commitee, in its Note to 104(b): ‘If preliminary questions of conditional relevancy were determined solely by the judge, as provided in subdivision (a), the functioning of the jury as a trier of fact would be greatly restricted and in some cases virtually destroyed. These are appropriate questions for juries. Accepted treatment, as provided in the rule, is consistent with that given fact questions generally. The judge makes a preliminary determination whether the foundation evidence is sufficient to support a finding of fulfillment of the condition. If so, the item is admitted. If after all the evidence on the issue is in, pro and con, the jury could reasonably conclude that fulfillment of the condition is not established, the issue is for them. If the evidence is not such as to allow a finding, the judge withdraws the matter from their consideration’.
Proof: Suppose without loss of generality that A is unconditionally irrelevant to F. Since B is positively conditionally relevant to F, conditional on A, we know that, in the presence of A, B is positively relevant to F. So, once the unconditionally irrelevant A has been introduced, introducing B as well will increase the probability of F. Thus, A and B are positively relevant as a package, Q.E.D. This result limits the application of the third prong, since the the pair of A and B will be jointly relevant whenever the first two prongs are satisfied and at least one of A or B is unconditionally irrelevant to F. That said, the relevance of the package of A and B does not settle the question of whether A and B pass a 403 analysis as a single unit, since A and B might be jointly prejudicial.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Kotzen, M. Conditional Relevance and Conditional Admissibility. Law and Philos 42, 237–283 (2023). https://doi.org/10.1007/s10982-022-09462-w
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10982-022-09462-w