first, bill o’reilly, has definitely got the meanings of dogma and doctrine wrong. i don’t remember the exact definitions but what he says is almost certainly not it.
second, we can’t disagree with doctrine. the church was given the authority and the power to teach infallibly on matters of faith and morals, and define doctrines on these.
the example he gives is not one of doctrine, but of practice. an incorrect understanding of doctrine and practice is the root of several misconceptions about the catholic faith.
doctrine includes things like trinity, resurrection, real presence, etc. these are never going to change. they are infallibly defined.
practice includes stuff like no meat on fridays, priestly celibacy, etc. these can be changed by the church as and when she sees fit. however, this does not mean that we are allowed to disagree with the church on these matters or disobey them. as long as the church told us to abstain from meat on fridays as a mortification, we were to do so in obedience.
what we are free to disagree on, are those things on which the church does not have a fixed position as yet(and may never have). this includes stuff like evolution/creation debate.
i hope this was of some help:blessyou: