Contraception has taken on a strange quality in Catholicism. It is a litmus test, and many treat it as an easy way to categorize your particular "brand" of Catholicism. Use contraception and think it is no deal? You are labeled a liberal Catholic, or maybe simply a "cafeteria Catholic" or an "American Catholic," where "American Catholic" is used as a pejorative. On the other hand, condemnation of contraception is seen as not only a sign of one's commitment to the Magisterium, but certainly one's membership in the ranks of the conservative Catholics - the self styled "traditionalists."
Certainly, the battle of words and ideas between these two forces within the Church is nothing new, but the use of this particular issue seems to have only heated up in the last fifty to sixty years - and, in some ways, the generations of Catholics in American growing up in the long shadows of the Second Vatican Council have inherited this litmus test as a given (well, at least any who give more than a passing moment's worth of thought to the matter).
As usual, the polarization has not only increased each side's zeal, but has decreased each side's ability to make compelling arguments. On the one hand, conservatives push two issues: the declarations of the Magisterium and their arguments from natural law. I have elsewhere discussed my critique of natural law, but the insistence that the immorality of contraception is a universally applicable (and, indeed, rationally demonstrable) ethical principle has only served to alienate the conservative Catholic voice; it may be that some set of arguments, carefully poised and hashed out with the right set of assumptions, could make a valid case against contraception, but more often these arguments consist of tired catch-phrases and begging the question (after all, if I begin with the assumption that it is immoral to separate the exercise of a bodily function from its natural purpose, I've already formed my conclusion that contraception is immoral - it is contained in the assumption).
Similarly, the "liberal Catholic" crowd seems to have attempted to move on from the debate entirely, no longer spending much time at all critically considering issues of contraception and its moral implications (except when those implications happen to coincide with certain left-leaning talking points, such as the environment - a liberal Catholic who would not even bother with you if you say contraception is a sin would probably become quite talkative if you mention that birth control pills might be permanently damaging the ecosystem).
Amidst all this, a more reasoned analysis of contraception seems improbable. But there are some common points that both sides tend to share, common assumptions that could form the basis of a more fruitful dialogue (and, perhaps, more fruitful compromises). Allow me to share what I believe to be the common concepts of both conservative and liberal Catholic appraisals of the contraception issue.
1. Contraceptive practices have grave social consequences.
Both sides accept the public, social nature of sexual practices. Though members of both sides (more likely, the liberal side) may plead the "private" character of what goes on in the bedroom, reproduction is a public issue. The creation of new citizens, who may potentially become either productive or parasitical and whose upbringing will be a strong determining factor in his future, bears with it a social responsibility. As such, there are grounds for the ethical treatment of contraception. Of course, this common belief is diverted by the question of in which direction social responsibility lies: are couples' primary duty to procreate (at a reasonable, but consistent, pace), thus providing society with new members and conforming with the natural function of sex, or is the primary duty to carefully withhold this procreative power in the light of increasing awareness of social and global problems related to population growth?
However, I claim that these two responsibilities are not ultimately contradictory, but are rather rendered so by the unnecessary dichotomizing of procreation and contraception. Pope John VI asks in the beginning of Humanae Vitae, "could it not be admitted that the intention of a less abundant but more rationalized fecundity might transform a materially sterilizing intervention into a licit and wise control of birth?" Of course, against the advice of the majority of his own commission on the subject, the Pontiff would go on to answer with a resounding "no." Yet the question seems to combine the concerns of both parties: a view of contraception as part of an overall fertile marriage, rather than a view of it as simply contrary to fertility. Perhaps revisiting this question could provide a source of common discussion on both sides, as long as conservatives are truly willing to consider that the use of contraception is not equivalent to a complete rejection of procreation and the liberals are willing to admit that a purely contraceptive sexual lifestyle may represent a kind of unsupportable turning against the functions of the body.
2. There are good reasons not to have children
While conservative Catholics often treat this part of Catholic teaching with a kind of begrudging acceptance, a corollary to the Church's condemnation of artificial contraception was the admission that there are indeed reasons why a couple could engage in sex without intending on procreation (that this admission is used as justification for natural birth control via natural family planning and not for artificial birth control seems to be, among other things, a failure in logic). This is actually a point of agreement with liberal Catholics: both groups recognize that the financial, emotional, and physical burdens of raising children are great, and that as such it is not to be taken lightly. The liberal Catholics perhaps have a far more extensive list of acceptable reasons, including concerns for the social aspect of procreation, its strain on global resources, and the impact on the environment (the very sorts of things Paul VI mentions in his introduction to the topic in Humanae Vitae).
Then, if there are valid reasons why a couple should wish to avoid having children, the conservative Catholic may wonder why he condones one means to this end and forbids another; what about the artificiality of contraceptive devices and pharmaceuticals makes them sinful in themselves? I will put to the side the issue of abortifacient contraceptives, concerns about which are of an entirely different nature. Simultaneously, cannot liberal Catholics (and, perhaps, liberals in general) approach the same question from a different angle, in order to concede that the responsibility of procreation (it is, indeed, an important duty of a species to reproduce, even if we have reason to moderate that activity) renders certain types of excuses invalid, and that couples with ample resources and time should seriously consider engaging in the same act without which they would not exist? After all, who hasn't seen the utter waste of a three-thousand plus square foot home, two middle class wage earners, two cars, and...no children.
3. Teenage pregnancies, abortions, unwanted children, and STD's are all indicative of social ills that need to be addressed
Conservative Catholics often blame contraception and the Sexual Revolution for these social ills, pointing their finger squarely in the faces of the liberal Catholics as being the ones whose imprudent endorsement of birth control and feminism are responsible for what can generally be called the overall smuttiness of society today. Liberal Catholics point the finger right back, maintaining that it is actually the stuffy and outdated sexual morals of the conservative forces in America that have prevented a true response to these issues in the form of better sexual education, better access to contraception, and the liberation of women from their role as reproductive vessels.
Both see these issues as bad, either in themselves or as indicators that all is not right in the world. And, yet again, we see a mirror image in their accusations. But if the truth is in the middle, the acknowledgement of these social ills and studies as to their causes and relationship to contraception and other variables might be a good place to start a more productive dialogue, especially if liberal Catholics will acknowledge that the unpinning of sexuality from procreation and the laissez faire attitude towards casual sexuality may be just as responsible for these issues as are a general lack of a sense of social sexual responsibility in society. Conservative Catholics can acknowledge that part of taking responsibility might come in the form of birth control as well as abstinence - an admission that merely needs history, even Catholic history, to back up the truth that many people will have sex with each other no matter how persuasively you might point out its immorality.