“We have, in fact, two kinds of morality side by side: one which we preach but do not practice, and another which we practice but seldom preach.”
- Bertrand Russell (Sceptical Essays (1928), “Eastern and Western Ideals of Happiness”)
We only preach principles because we see them as higher ideals to strive for, rather than as ways of life that are unconditional to happiness. If everyone involuntarily assumed that certain principles, as “thou shalt not murder”, are ones to be taken for granted, there would be no purpose to preach them because it’s expected. In retrospect, we preach principles because we already assume half-heartedly that the masses will still adhere to certain actions regardless of hearing the preaching.