as a matter of principle
idiomPart ofprinciple
as a matter of principle — idiom
1. because of your personal moral beliefs, not for practical, financial, or emotion
1.idiom
Definition
because of your personal moral beliefs, not for practical, financial, or emotional reasons
Example
Maeve returned the extra change to the cashier as a matter of principle.
Hamza refused the job offer as a matter of principle when he learned the company had broken safety laws.