The answer is simple Trid... those who insist and believe in the absolute purity and infallibility of magisterial teaching believe (and therefore "act") in a manner that is contrary to the laws of nature. Given that we know ALL things change and grow with knowledge, maturity, etc., and that includes the Body of Christ, His Church. So as Catholic Christians we are either wedded to the laws of nature (based on reality and Christocentric thought) or Natural Law theory which is an outdated philosophy based on black-white thinking and does not comport with our understanding of modern human behavior. The sad truth is, black and white thinking causes war and division and has little to do with loving God and neighbor.