In my cursory and anecdotal study of human nature, I've noticed that those most loud and sure about their own opinions tend to love to vilify the views of others instead of fairly assessing and evaluating alternative points of view. Aristotle once said that it is the mark of an educated mind to be able to entertain various points of view on the same subject without necessarily accepting them, and I tend to think he was right about that.
Needless to say, many of these self-righteous and close-minded ideologues love to preach and to pontificate, and they tend to never wonder whether keeping an open mind and being critically curious might not be a better alternative to having made up one's mind before having sufficient evidence to draw a conclusion one way or the other.
And because these folks rarely question whether their strongly-held views are consistent with each other, people like comedian George Carlin (doing the modern comedic equivalent of Socrates' job as a gadfly) get to put them on the spot and make an awesome mockery of the incoherence and inconsistency of their views, as he does on this skit about abortion, animal rights, religion, and the sanctity of life... You've been warned :)
One could lead a few lectures on Nietzsche's hermeneutic circle; Hobbes' psychological egoism, contractarianism and his theory of rights; Peter Singer's views on abortion, utilitarianism, animal rights, and much more just off these 12 minutes... Thanks, George Carlin!
For more on our inevitably biased point of view, check out Douglas Adams meditate on where the concept of God comes from.
And remember, chickens are decent people, so please be kinder to them and other animals.