A typical physical law like Conservation of Momentum, that is practically an absolute in today's view of physics, but if mutability is indeed a universal principle, then there will occur events in which articles collide and momentum is not conserved. One can very well say "Point out please such an event" and I can't, but if the Principle of Mutability makes sense, there must exist such processes --Extremes, as in the atmosphere of black hole, momentum conservation will take on a new character, momentum will be taken up somehow by the black hole. You can say it's not so much that the conservation of momentum is violated, as it's transcended, it goes into a new form, a new agency takes up momentum, the black hole itself. So it's in that sense that I regard the principle of mutability, the physical laws as a useful guide in recognizing the existence of the processes that might otherwise be overlooked.