In old days, irrationals were inferred as the supposed limits of series of rationals which had no rational limit; but the objection to this procedure was that it left the existence of irrationals merely optative, and for this reason the stricter methods of the present day no longer tolerate such a definition.
"Mysticism and Logic and Other Essays"
Bertrand Russell
In the Greek language this is expressed by a difference of mood; the subjunctive being the construction equivalent to may, the optative to might.
"The English Language"
Robert Gordon Latham
In the following, an aorist is followed not by an optative, but by a subjunctive.
"The English Language"
Robert Gordon Latham