an open question

an open ˈquestion

(also open to ˈquestion) a matter that cannot be decided easily or that people hold several different views on: Whether private schools give children a better education is open to question.It’s an open question whether meat is bad for you.
See also: open, question
References in classic literature ?
Aye, aye, make him sit down," said several voices at once, well pleased that the reality of ghosts remained still an open question.
Miss Miggs, who had fallen into a terrible state of grief when the first part of this sentence was spoken, recovered a little at the second, and seemed by the sudden check she put upon her tears, to intimate that possibly this arrangement might meet her views; and that it might, perhaps, remain an open question.
We know that mind has the power to maintain substance even though it may not be able to create substance--the latter is still an open question.
As Perry had discovered among the writings of her kind in the buried city of Phutra, it was still an open question among the Mahars as to whether man pos-sessed means of intelligent communication or the power of reason.
The ape-man could not rise, therefore, without pushing the lion away and whether Numa would tolerate being pushed was an open question.
With no business capacity, old and opinionated, he was land poor, and it was an open question which would arrive first, his death or bankruptcy.
If you asked me for another penny, and made it an open question, I'd repent of being so liberal and knock off half-a-crown.
Powell said there's been no decision on whether the Fed would move back to the prior methodology, and remains an open question in the long run.
Terri Langford writes that how instrumental Perry was in improving it remains an open question.
And of course, he invited 300 voters along to an open question and answer session.
In a speech at London's City University, Mr Grieve, 55, said: "It is still an open question whether something said in Parliament in breach of a court order may be repeated in the Press.
What legal texts may eventually require amendment is an open question that must be explored, while remaining aware of the different procedures that would be required to amend the various legal instruments,' he said, referring to the fact that any changes would force a referendum in Ireland, which rejected the Lisbon Treaty in a 2008 vote.
REAL MADRID midfielder Rafael van der Vaart has refuted reports linking him with Chelsea, insisting his future remains an open question.
The Border Service will not merge with the Defense Ministry and will remain a separate agency, said press service of the Kyrgyz Border Service commenting on media reports citing Border Service Chair Zamir Moldoshev who said during session of the parliamentary faction of the Social Democratic Party of Kyrgyzstan on January 21 that merger of the Border Service with the Defense Ministry is an open question.
Whether it's an accurate harbinger of things to come remains an open question.