Definition
A state of irreconcilable conflict or logical incompatibility between two or more things — statements, positions, pleadings, verdicts, or legal provisions — such that both cannot simultaneously be true, valid, or operative.
In legal usage, inconsistency arises across several distinct contexts:
1. Testimonial inconsistency: A conflict between a witness's trial testimony and a prior statement made out of court, or between two statements made by the same witness at different times. The inconsistency may be used to impeach the witness's credibility or, under certain conditions, as substantive evidence.
2. Inconsistency in pleadings: A conflict between alternative claims, defenses, or factual allegations within a party's own pleadings. Modern procedural rules permit inconsistent pleadings in the alternative; what is forbidden is the assertion of positions so contradictory as to be fundamentally dishonest or to constitute judicial estoppel.
3. Inconsistency between verdicts: A conflict within a jury's findings — for example, between answers to special interrogatories, or between a general verdict and a special finding — that cannot be reconciled by any reasonable reading of the evidence.
4. Inconsistency between legal provisions: A conflict between two statutes, regulations, or clauses in a contract or instrument such that both cannot be given full effect. Courts resolve such conflicts through rules of construction: the specific controls the general, the later in time controls the earlier, and so forth.
Common Language
Modern common usage (Wiktionary): The quality of being inconsistent; the state of lacking agreement, harmony, or compatibility between things; also, a specific instance of contradiction or incongruity.
Historical common usage (Webster's 1913): "The quality or state of being inconsistent; discordance in respect to sentiment or action; such contrariety between two things that both cannot exist or be true together; incompatibility."
The ordinary meaning is close to the legal meaning, but the gap matters in one important direction: in common usage, inconsistency is a matter of degree — things can be "somewhat inconsistent." In legal usage, the standard is often binary and context-dependent. A prior statement is not legally "inconsistent" for impeachment purposes merely because it differs in emphasis or omits detail; courts apply a threshold of material or substantial contradiction. Similarly, two statutory provisions are not "inconsistent" in the legal sense unless they cannot reasonably be reconciled by construction. Researchers should not assume that the ordinary intuition of inconsistency maps directly onto the doctrinal test.
Common Confusion
Inconsistency is frequently conflated with contradiction, but courts and commentators distinguish between them. A contradiction is a direct denial of a prior assertion — the witness said X then said not-X. An inconsistency is broader: it includes statements that are logically incompatible without being direct negations, as well as prior silence or omission where a reasonable person would have spoken. Under Federal Rule of Evidence 613 and its state analogs, courts generally treat any prior statement that "tends to contradict" current testimony as sufficient for impeachment, but the precise threshold varies by jurisdiction and context.
Inconsistency in pleadings should not be confused with amendment of pleadings. A party who amends a pleading as of right has abandoned the earlier position; the question of whether prior inconsistent pleadings may be used against that party as admissions is a separate and contested doctrine.
Why It Matters in Research
The concept is a research hub connecting evidentiary, procedural, and substantive doctrines that use the same word to mean related but technically distinct things. A researcher who encounters "inconsistency" in a legal source must first identify which domain is implicated before the term becomes useful.
For evidence researchers: The critical distinction is between prior inconsistent statements used only to impeach (going to credibility) and those admissible as substantive evidence. At common law, prior inconsistent statements were inadmissible for their truth. Modern federal and many state rules changed this — but only for statements made under oath at a prior proceeding. Historical sources from before the mid-twentieth century are therefore unreliable guides to current doctrine on this point. The Rapalje & Lawrence entry reflects the common-law baseline and should be read accordingly.
For procedural researchers: The permissibility of inconsistent pleadings in the alternative is a distinctly modern development. At common law, election of remedies and consistency requirements were strict. Researchers working in pre-code jurisdictions or equity courts will find a much narrower tolerance for pleading inconsistency than modern federal practice allows.
For statutory construction researchers: The tools for resolving inter-provision inconsistency are ancient and relatively stable, but their application is highly fact-specific. Secondary sources often state the canons abstractly; the real research work is in finding how courts have applied them to analogous textual conflicts.
A persistent trap in historical sources: older treatises and dictionaries frequently discuss "repugnancy" where modern sources say "inconsistency." The two terms overlap substantially but are not identical, and the older term carries specific technical meaning in deed and will construction that "inconsistency" does not fully capture.
Historical Dictionary Support
Rapalje & Lawrence treat inconsistency primarily in the testimonial context, defining it as a material variance between statements of the same witness that tends to show the witness cannot be relied upon. The entry reflects the classical impeachment framework in which prior inconsistent statements served a purely credentialed function — discrediting the witness — without constituting evidence of the truth of either statement. This is the common-law baseline.
What Rapalje & Lawrence do not address, by reason of their era, is the subsequent doctrinal development under codified evidence rules that elevated certain prior inconsistent statements to the status of substantive evidence. The entry is therefore useful as a baseline for understanding what historical courts meant when they spoke of impeachment by inconsistency, but it should not be used to characterize current federal or modern state doctrine without supplementation.
The dictionary is also silent on inconsistency in pleadings and statutory construction, reflecting a period when those doctrines were either undeveloped as distinct categories or addressed under separate headings (repugnancy, election of remedies, surplusage).
Encyclopedia Cross-Reference
Impeachment by Prior Inconsistent Statement — Rule 613 (civpro_176), The Law Mind Civil Procedure & Evidence Encyclopedia. Direct treatment of the evidentiary doctrine; the primary encyclopedia reference for testimonial inconsistency.
Prior Statements of Witnesses — Rule 801(d)(1) (Inconsistent, Consistent, Identification) (civpro_182), The Law Mind Civil Procedure & Evidence Encyclopedia. Covers the conditions under which prior inconsistent statements cross from impeachment use to substantive admissibility — the doctrinal development that Rapalje & Lawrence do not reach.