It is a main thrust of philosophical Liberalism (and of ancient Stoicism) that human beings have a duty to rise above not only animal but parochial and sectarian passions. Any attempt to justify revenge must therefore represent a step back toward the jungle from which we escaped all too recently.
No argument drawn from biological necessity would impress philosophers who, since the Enlightenment, have often written as if man were either naturally good or was only weakly endowed with a bundle of propensities known by philosophers as human nature or, by Christians, as “the old Adam.”
Revenge and marriage, as the institutionalized means of expressing love and hate, have much in common: Both are found in a variety of forms, but the forms and tendencies that converge in societies around the globe encourage us to think of them as generically human phenomena
Robert E. Lee, who in so many ways epitomized the highest ideas of Christian civility, summed up the common feeling in his famous statement that, “Duty is the most sublime word in our language,” adding the injunction: “Do your duty in all things. You cannot do more, you should never wish to do less.”
Most modern schools of philosophy base morality on the principles of reason, and the principal accounts of moral development emphasize growth in moral reasoning rather than moral behavior. To be a human person in this sense would mean that an individual is conscious of his own existence and capable of making rational decisions, including the decision to remain alive.
On abortion and other forms of infanticide, Nature gives us the sort of answer she always gives–general rules and statistical averages to which there are exceptions, but, from the Christian perspective, Nature is the tarnished mirror in which we can only glimpse, obscurely, the true reality
The obligation to care for one’s offspring is a human universal, like the incest taboo or the prohibition of murder. Human and primate mothers, as a rule, devote themselves to their children, and mother-love is regarded conventionally as the most selfless and irrational forms of human attachment.
I brought up movies only because many of my favorites have a fair amount of violence in them, and you seem to be lumping violence with pornography.