The phrase "principal change" is correct and usable in written English, and it can be used to refer to a fundamental alteration or shift in an idea, opinion, or position.
For example, "The principle change in the company's policy has made it more competitive in the market."
Yes, people can in principle change their religion.
In science, if an experiment produces results that are contrary to one's belief the scientist should, in principle, change her mind.
Moreover, as the concept of a conditional was also meant to provide for logical consequence between premises and conclusion, this leads to the problematic result that arguments can in principle change from being valid to being invalid and vice versa.
The principle change to the skull with leprosy is rhinomaxillary syndrome, which involves loss of bone around the pyriform aperture, destruction of the nasal spine, and loss of bone at the anterior alveolar process [5], [6], [18], [44], [45].
Rather, it appears that the principle change required is a reevaluation of the premise apparently shared by most antitrust enforcers that health insurers consistently act as surrogates for consumers.
There has been increasing acknowledgment of the fact that internal noise at cellular level - low number of molecules [ 68- 70] - can in principle change qualitatively the behavior of the system with respect to the one predicted from noise-free (deterministic) modeling: noise-induced stabilization [ 71], noise-induced oscillations [ 29].
In principle, changes in the prior definition of parameters should not alter the posterior estimations.
In principle, changes in the glucose concentration within the aqueous could directly cause refractive change.
After ten correct responses in a row, the sorting principle changes.
In principle, changes in circulating miRNAs should be the net effect of altered secretion, degradation, and cellular uptake.
In principle, changes could occur in the number of responding islets, number of beta cells or in the secretory function of individual beta cells.
