E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Open Question (An).
A statement, proposal, doctrine, or supposed fact, respecting which each individual is allowed to entertain his own private opinion. In the House of Commons every member may vote as he likes, regardless of party politics, on an open question. In the Anglican Church it is an open question whether the Lords Supper should be taken fasting (before breakfast), or whether it may be taken at noon, or in the evening. Indubitably the institution was founded by Christ after supper; but Catholics and the High Ritualistic party insist on its being taken fasting.