Definition
A person historically disqualified from serving as a witness in legal proceedings on the ground that they lacked belief in a God who rewards and punishes, either in this world or the next, and therefore could not be bound by the oath administered in court. The operative legal question was never theological conviction in the abstract but competency to testify under oath: a witness who did not believe that God would punish perjury was thought to have no meaningful obligation to tell the truth, rendering their testimony inadmissible.
Three overlapping formulations appear across the historical dictionaries:
1. One who does not believe in the existence of a God who will reward or punish in this world or that which is to come.
2. One who professes no religion that can bind his conscience to speak the truth.
3. One who does not recognize the inspiration or obligation of the Holy Scriptures or the generally recognized features of the Christian religion.
These definitions are not identical. The first is the broadest and most defensible on its own terms — it focuses on belief in divine sanction, not on any particular creed. The second is functional — it ties disqualification directly to the oath mechanism. The third, associated with Anderson and with certain New York authority, is the narrowest and most explicitly Christian, suggesting that non-Christian religions might be insufficient to qualify a witness regardless of sincere theistic belief.
Common Language
Modern common usage (Wiktionary): A person who rejects or does not hold a specific religion; often used as a term of opposition by adherents of one faith toward outsiders.
Historical common usage (Webster's 1913): One who does not believe in the inspiration of the Scriptures or the supernatural origin of Christianity; a freethinker.
The gap between common and legal usage here is consequential. In ordinary speech, "infidel" is a term of religious classification — it describes what a person believes or disbelieves about a faith. In its legal application, the term was a term of procedural competency. The legal question was not whether a witness held orthodox Christian doctrine but whether their belief system could support a binding oath. These are related but distinct inquiries, and the conflation of religious identity with testimonial incompetency was the source of considerable doctrinal confusion and gradual reform.
Common Confusion
The term was applied inconsistently to atheists, deists, Jews, Muslims, and members of non-Christian faiths — groups whose disqualification rested on very different grounds. An atheist rejects divine existence entirely; a Jew or Muslim holds a robust theistic belief with attendant moral obligations to truth-telling. Courts and commentators who treated all of these as "infidels" were collapsing the functional test (will this oath bind the conscience?) into a sectarian one (does this person hold Christian beliefs?). The reform of competency rules in the nineteenth century was driven in part by the absurdity of this conflation. Rapalje & Lawrence notes that "formerly infidels were incompetent" — the past tense is significant and reflects the trajectory of the law by the time those dictionaries were compiled.
Why It Matters in Research
This term is almost entirely a historical artifact in modern law. Statutory and constitutional reforms across American jurisdictions during the nineteenth century abolished religious belief as a prerequisite for testimonial competency. Researchers encountering "infidel" in primary sources should treat it as a marker of the older common-law competency framework, not as a continuing rule.
Several traps await the unwary researcher:
First, the definitional instability across sources is genuine, not merely a matter of competing word choices. The Christian-centered definition in Anderson (and the New York authorities it draws on) represents a more restrictive line than the divine-sanction formulation in Black's and Bouvier. Case outcomes in mid-nineteenth-century American courts varied depending on which definition the tribunal applied.
Second, the Greenleaf citation (1 Greenl. Ev. § 368) appears across multiple dictionaries as the standard authority for the functional definition. Simon Greenleaf's Treatise on the Law of Evidence was the dominant American evidence treatise of its era, and his framing — religion that can bind conscience to speak the truth — was more accommodating of non-Christian witnesses than the Anderson formulation. Researchers tracing the reform debate will want to work with Greenleaf directly.
Third, the Rapalje & Lawrence entry is partially garbled in the surviving text, with content from an unrelated entry on respiration apparently interpolated. The reliable substance is the concluding observation about former incompetency and the implicit acknowledgment that the rule had changed.
Fourth, corpus connections run directly to evidence law, oath law, and the law of witness competency. The infidel disqualification is part of the same doctrinal cluster as the rules excluding atheists, convicted felons, and parties to suits — all of which were reformed or abolished on similar grounds over the course of the nineteenth century.
Historical Dictionary Support
The historical dictionaries present a broadly consistent picture with important differences in framing. Black's (both editions), Bouvier, and Greenleaf converge on the divine-sanction formulation as the operative test. This framing is more defensible and more liberal: it would admit a sincere Muslim, Jew, or member of any tradition that imposes an obligation of truthfulness backed by divine judgment.
Anderson and the New York authority at 37 N.Y. 580 represent the more restrictive Christian-centered view. Anderson's definition — one who does not recognize the inspiration or obligation of the Holy Scriptures or generally recognized features of the Christian religion — would exclude any non-Christian witness regardless of sincere theistic belief. This was not the universal rule even at the height of the doctrine, but it was a real line of authority.
Rapalje & Lawrence's description of the infidel as a "disbeliever in Christianity and the truths of the Scriptures; a freethinker" likewise reflects the more sectarian formulation, though the text of that entry is too corrupted to draw firm conclusions.
What none of the historical dictionaries adequately address is the mechanism of reform. They describe the old rule with varying degrees of qualification but do not systematically trace the statutory changes that had already altered or abolished the disqualification in most American jurisdictions by the time these dictionaries were in wide use. Researchers should not assume that a dictionary entry describing the rule represents the law in force at the time of the source they are examining.
Jurisdictional Note
American jurisdictions largely abolished religious tests for witness competency through statutory reform during the nineteenth century, with significant variation in timing. English law retained some vestige of the requirement longer. Any research touching on a specific jurisdiction and time period requires direct examination of that jurisdiction's evidence statutes and court rules — dictionary definitions alone are insufficient to determine whether the disqualification was in force.