Definition
A condition single is a contractual or conveyancing condition that imposes one obligation only — requiring the obligated party to do (or refrain from) a single specified act. It stands in contrast to a condition involving multiple requirements or alternatives. The term appears primarily in the law of deeds, bonds, and conveyances, where the instrument spells out a single performance as the operative condition on which rights vest, are forfeited, or are discharged.
Common Confusion
Condition single should not be confused with "condition precedent" or "condition subsequent," which describe the temporal relationship between a condition and the legal consequence it governs. Condition single describes the structure of the obligation (one act required), not its timing or effect. A condition single may be either precedent or subsequent. Researchers should also distinguish condition single from "single condition" used loosely in modern contract drafting, where the phrase carries no technical meaning.
Why It Matters in Research
Researchers encountering "condition single" will find it almost exclusively in older property and conveyancing materials, particularly those working within the tradition of Sheppard's Touchstone of Common Assurances (17th century). The term is taxonomic — it helped historical drafters and courts classify conditions to determine the rules governing performance, breach, and relief. Understanding whether a condition was single, copulative (requiring multiple acts), or disjunctive (offering alternatives) could determine whether partial performance satisfied the condition or whether strict compliance was required.
The term rarely appears in modern case law or statutes by name. A researcher finding "condition single" in a historical deed, bond, or pleading should treat it as a signal to consult the property and conveyancing sections of the historical corpus rather than modern contract doctrine. The concept survives in substance — courts still distinguish conditions requiring a single act from those requiring multiple or alternative performances — but the vocabulary has largely dropped away in favor of plain-language drafting and modern contract terminology.
Cross-corpus researchers should note that "condition single" belongs to a cluster of condition-classification terms (see RELATED TERMS) that structured pre-modern conveyancing analysis. Encountering one term in a historical source is often a cue to look for the others in the same instrument or treatise passage.
Historical Dictionary Support
Black's Law Dictionary and Burrill's Law Dictionary are in exact agreement, both defining condition single as "a condition to do one thing only" and both citing the same authority: Sheppard's Touchstone (Touch. 118). This unanimity reflects the term's character as a settled taxonomic label rather than a contested legal concept. Neither dictionary elaborates beyond the one-sentence definition, which itself signals that the term's function was primarily classificatory — giving practitioners a shared vocabulary for distinguishing condition types rather than establishing a doctrinal test.
The brevity of both entries is instructive for researchers: the historical dictionaries treat this as a term of art that would have been immediately understood by practitioners trained in common assurances and bond practice. Modern dictionaries have largely dropped the entry, reflecting the decline of formal condition taxonomy in contemporary drafting and litigation.