A pair of statements may be taken conjunctively or disjunctively; for example, "It lightens and it thunders ," is **conjunctive**, "It lightens or it thunders" is disjunctive. Each such individual act of connecting a pair of statements is a new monad for the mathematician .

— p. 268 (Mathematical Monads (1889))

A system is said to be coherent if every fact in the system is related every other fact in the system by relations that are not merely **conjunctive**. A deductive system affords a good example of a coherent system.

— Lizzie Susan Stebbing (1930)