1911 Encyclopædia Britannica/Alternation

ALTERNATION (from Lat. alternare, to do by turns), strictly, the process of “alternating,” i.e. of two things following one another regularly by turns, as night alternates with day. A somewhat different sense is attached to some usages of the derivatives. Thus, in American political representative bodies and in the case of company directors, a substitute is sometimes called an “alternate.” An “alternative” is that which is offered as a choice of two things, the acceptance of the one implying the rejection of the other. It is incorrect to speak of more than two alternatives, though Mr Gladstone wrote in 1857 of a fourth (Oxf. Essays, 26). When there is only one course open there is said to be no alternative.