The phrase "a philosophical issue" is correct and usable in written English.
It can be used when discussing topics that involve fundamental questions about existence, knowledge, values, reason, mind, and language.
Example: "The debate over free will versus determinism is a significant philosophical issue that has puzzled thinkers for centuries."
Alternatives: "a philosophical question" or "a philosophical dilemma".
It is, of course, a philosophical issue that goes back to Plato (and modern philosophers who assert the natural existence of mathematical ideas are called platonists).
"Regulatory reform is not a philosophical issue.
For others it is a philosophical issue.
There is a philosophical issue at stake here, too.
And I don't think this is a philosophical issue.
"But there is a philosophical issue, do you want these people paying taxes?
"Saul almost single-handedly changed that". Paul Boghossian, a former student of Mr. Kripke's, who now teaches at New York University, said, "The great thing about Saul is that he never confuses a real philosophical issue with a merely technical problem". Except on very rare occasions, Mr. Kripke does not actually set words down on paper.
If in June it comes down to a fight between Jerusalem and War Horse, a perennial philosophical issue will arise: should voters consider the text of a play, or its entire production?
The role and correct account of equality, understood as an issue of social justice, is itself a difficult philosophical issue.
In most dialogues, however, the speakers clearly concur on a certain philosophical issue or one of the positions defended by a particular disputant is clearly more convincing than the positions defended by others.
Given overhauling the RDA is a core philosophical issue for elements of the right of the Liberal party, a strong showing of support in the Senate will likely trigger a copycat process in the House of Representatives, which would further complicate efforts by the prime minister to keep a lid on the issue.
