While recognizing the dangers of trying to be too wide ranging in subject matter in the limited space of a blog post, my goal here is to set out answers to the following:
- What is a "contraceptive mentality"?
- How is a contraceptive mentality contrary to how humans are "meant" to function morally and sexually?
- How, if at all, does NFP (natural family planning) relate to a contraceptive mentality?
I think it's easiest to think about the idea of a contraceptive mentality against the backdrop of how we function sexually as human creatures -- a term I use advisedly in that I want to emphasize our rootedness in a certain biological reality of being primates with certain biological systems and instincts, while at the same time not ignoring our rational, emotional and moral sensibilities in the sense that "human animal" strikes me as implying.
Uncertainty and Conception
One thing that sets us apart from most other higher primates is that humans have fairly even sexual drive all of the time. Or, at least, men have sexual drive pretty much all of the time. Women seem to have more variation in their level of interest, and indeed there is a fair amount of evidence that one driving (though unconscious) element of their drive is that they are more "in the mood" during the times of the month when they are fertile than when they are not. Another thing that sets us apart from most other higher primates is that a woman's fertility is not marked by unmistakable physical signs (change of color and swelling of the genital area, changes in smell, etc.) (Though Bonobos have often been compared to humans in regards to their relatively constant sex drive, they are like chimps in that female fertility is readily apparent through external signs.)
Thinking about humans naturalistically, this makes a fair amount of sense from an evolutionary point of view. The exceptionally long period it takes for human offspring to reach maturity, and the importance of learning social/cultural patterns in order to function maturely as a human, makes rearing by stable family groups highly desirable. Other higher primates, with their visually obvious mating periods, do not tend to form strong pair-bonds between mates. Indeed, quite the contrary: because a female's fertility is obvious to all males, the tendency among chimps, gorillas, etc., is for any adult male who can get within reach of her to try to get his genes into play. There are a number of different approaches a male primate may use in order to try to assure he is the one who succeeds in fathering a child on her, but there's a fair amount of competition and free-for-all involved. For humans, since it isn't immediately obvious when a woman is fertile, a male stands the best chance of passing on his genes by forming a longer term, exclusive relationship, since it's only by having relations consistently over at least a month (and knowing that other males have not succeeded in getting in on the action) that he can have reasonable assurance of being the father of any offspring. Take this relative exclusivity out into years instead of months (with the incentive of successfully fathering multiple offspring) and you've solved the problem of having both parents around to help rear offspring which take a long time to mature.
Evolutionarily speaking, there are differing incentives for men and women, which can be used to sketch different stories about men's and women's sexual drives and instincts. But I don't think it's overly controversial to assert that a compromise which suits both sets of drives well is found in monogamy, serial monogamy or polygamy -- relationship dynamics which are exclusive and stable, though not necessarily equal. (As the prevalence of polygamy in many cultures illustrates -- there's nothing but upside for a male from an evolutionary point of view if he can have exclusive access to multiple women rather than just one.)
All of which is a long way of coming around to this basic point: Uncertainty about when conception can result from intercourse is a factor which has been central to shaping the development of human sexual and relationship dynamics throughout the existence of our species.
Evolution vs. Responsible Parenthood
The above discussion should immediately bring to mind a contrast between our modern attitudes toward reproduction and what in anthropomorphic terms we might term evolution's "motivation": A host of messages in our modern society tell us that we should limit the number of children that we have, while "evolutionary success" is based upon the number of grandchildren one has who survive to reproduce. Thus, while the instincts and physical characteristics of most animals seem centered on maximizing the number of offspring, those of us in modern society tend to focus on not having more children than we plan on (and often plan on few.)
It's common for Christians of a ruralist tenor to attribute this to modern industrial society, asserting that in an agricultural society children are an asset while in an industrial society they are a liability. I think, however, this is the result of simplistic thinking. I would propose that, ever since we became aware, humans have always sought some degree of "responsible parenthood", though it's true that the cultures of many modern developed nations are much more biased against childbearing than most throughout history. Still, even in societies in which large numbers of children were described invariably as a blessing, we as humans have, because we are conscious and see death and deprivation as evils, always sought to have the "right" number of children for a given time and place.
Evolution is a process which optimizes the success of populations, not of individuals. As such, it is evolutionarily advantageous for members of a population to produce more offspring than their environment is easily able to sustain. This achieves several advantages: More individuals means more genetic variation, thus providing a larger chance for the development of advantageous new traits. Large numbers of individuals also protect against unforeseen catastrophes and provide individuals able to exploit unforeseen opportunities (new niches, migration, competition, etc.) If available resources prove not to be enough, the least fit individuals will die off, which for the genetic population as a whole is also generally beneficial.
However, we as conscious and moral beings obviously don't want to see people suffering for lack of food or other necessities. However advantageous it might be for the population, we don't want to see people suffering for lack of basic resources. And so we naturally want to avoid having children at times when we think we cannot support them.
[to be continued]