"strict principle" is correct and can be used in written English.
You can use it when referring to a rule or standard that is strictly adhered to, for example: "My parents have always lived by a strict principle of treating everyone with respect."
And this strict principle, unless there is relief by the statute, is seen in modern cases.
First, because hers was a short marriage, lasting just four years, so the strict principle of equality did not apply.
Another trend that developed in the Sāsānian period, although it had already made itself felt under the Arsacids, was a strict principle of dynastic legitimacy.
The striped paintings, made according to a strict principle, are as boring as the method itself and seeing so many at the Fruitmarket Gallery only makes one conscious of the difference between permutation and actual variety.
That case provided "persuasive support" for the argument that article 10, at least, was not limited by the same strict principle of territoriality as applies to other parts of the Convention.
Canada's Mr Harper, for example, did not make his choice as a matter of strict principle: note his willingness to pay enthusiastic visits to China, a far more authoritarian country.
At a crucial age in his intellectual development, he was brought up in the strict principles of Protestantism.
Kant's conception of morality as a matter of rigid adherence to strict principles emerges as partly an intended remedy for his own hypochondria.
In an interview before he left, he declined to say where he was going, but said he planned to apply the same strict principles as in his mountain expeditions: no support staff, minimal gear and no emergency communications equipment.
He thereby refuses to rely on abstruse methods through philosophical considerations and instead submits his work to the strict principles of the modern scientific method, centuries before its time.
Vico wrote: modern jurisprudence "examines the truth of the bare fact" which is constrained or ordered by the "strict principles of law". This jurisprudence is practiced by "human governments namely democracies, and especially monarchies" (Id., 407).
