The phrase "asserted in principle" is correct and usable in written English.
It can be used when discussing a statement or belief that is claimed to be true in a general or theoretical sense, rather than in a specific or practical context.
Example: "The theory was asserted in principle, but further research is needed to validate its application in real-world scenarios."
Alternatives: "claimed in theory" or "stated in principle."
Five days later he was stabbed to death by John Felton, a naval lieutenant who had served in his campaigns and who misguidedly believed that he was acting in defense of principles asserted in the House of Commons.
Yet the Doctrine of Discovery prevails, he asserts, so long as the "principle has been asserted in the first instance, and afterwards sustained".
However extravagant the pretension of converting the discovery of an inhabited country into conquest may appear, if the principle has been asserted in the first instance, and afterwards sustained; if a country has been acquired and held under it; if the property of the great mass of the community originates in it, it becomes the law of the land, and cannot be questioned.
Feinberg's principle reads as follows: "it is always a good reason in support of a proposed criminal prohibition that it would probably be an effective way of preventing serious offense...to persons other than the actor, and that it is probably a necessary means to that end...The principle asserts, in effect, that the prevention of offensive conduct is properly the state's business" (1985, 1).
"We will ensure that this is a successful permanent reform to our immigration system that will not need to be revisited," the group asserts in its statement of principles.
Sit-ins at lunch counters asserted a principle of equality against business owners' traditional legal right to decide whom to admit to their places.
In the Rayonist manifesto of 1913, he asserted the principle of the reduction of form in figure and landscape compositions into rays of reflected light.
President Obama firmly asserted that principle on the campaign trail in 2008.
The bill asserted the principle of the minimum wage in the fullest and clearest possible terms, subject to the provision of adequate safeguards against abuse.
The principle of univocalness asserts (in a somewhat anachronistic formulation) that any one theory, even any one among a set of empirically equivalent theories, should provide a univocal representation of nature by determining for itself an isomorphic set of models.
