Intro to Nature: Part Three
Today, we are going to address some ambiguities with regard to the way we often use the word “nature,” building on the last posts. Last time, we finished discussing Fr. Wallace’s two-fold conception of nature, breaking it down into (1) natural things and (2) their activities. When combined, natural things and their behaviors make up the whole world of nature. We emphasized strongly in our last post the importance of inherent natures, which are both the source of and that in virtue of which natural things live-out their particular behaviors and activities. In today’s post, we are going to talk in more detail about specific natures and why distinguishing them is so important for deciding what is natural and unnatural.
It is a mistake to use the word “nature” univocally, which means to treat all senses of a word as if they were the same. We often fail to distinguish “nature” in a general sense—the sense which characterizes the whole world of nature—from substances which have specific natures and activities which derive from those natures. We often do not realize that when we call something “natural” or “unnatural,” we actually mean that it’s either natural or unnatural in a certain way or a certain respect. Remember the example in our last post about the dog wearing a Halloween costume? For dogs to wear clothing is unnatural – it doesn’t belong to a dog’s nature to wear clothes. But we can still say that it is natural for human beings to wear clothing (we’ll discuss this in more detail later).
To make matters more complicated (or more fun depending how you look at it!) the same activity could be considered either natural or unnatural for a subject, depending on which way you look at it. For instance, it is “natural” for beavers to eat potato chips when they are offered them, insofar as they are animals, and animals need to eat to survive. If you starve a beaver and then offer it Doritos, it will eat them. But potato chips are not a typical food for a beaver. A beaver does not seek and find potato chips in its natural habitat; in fact, we would find it odd and “unnatural” for a beaver to seek out, eat, or crave potato chips. We know what a beaver is, and a potato-chip-eater is not what comes to mind. So in this case, it is the specific nature of the beaver that makes the eating of potato chips unnatural. Eating potato chips is both natural and unnatural for a beaver, depending on how you look at it.
Now, humans are defined as rational animals. Our rational nature is what sets us apart from other animals, and we engage in particular activities in virtue of our rationality. When we use our reason to deliberate and make decisions, when we use our free-will to act on our choices, this is natural for us. Recall what we said about how it is natural for human beings to wear clothing. St. Thomas makes this helpful distinction in the Summa (while discussing marriage, no less!):
A thing is said to be natural in two ways. First, as resulting of necessity from the principles of nature; thus upward movement is natural to fire. In this way matrimony is not natural, nor are any of those things that come to pass at the intervention or motion of the free-will. Secondly, that is said to be natural to which nature inclines although it comes to pass through the intervention of the free-will; thus acts of virtue and the virtues themselves are called natural; and in this way matrimony is natural, because natural reason inclines thereto in two ways.
What St. Thomas explains here is that interventions on the part of our free will are unnatural in one sense, and natural in another. Using matrimony as an example, he explains that some things that humans do are not natural in the sense that they “just happen” according to the world of nature, e.g., the way that fire tending upwards “just happens.” However, some things that arise from intervention or force can be natural insofar as the impulse for them comes from our nature. So, we don’t just somehow “become married” by natural forces; We choose to marry. However, we do so because we naturally seek union with someone of the opposite sex in order to help rear, educate, love our children. It is reasonable. Likewise, human beings wear clothing not only because it protects us from the elements, but also to adorn ourselves and to safeguard modesty. To wear clothing therefore follows from our nature, as it is a reasonable thing to do.
In our next and last post, we are going to wrap up our discussion on nature by using what we have learned to tackle a moral dilemma. Remember our friend from Part One, who argued that contraception is no different than any other “natural” process? Well, next we are going to show how this position falls into the very trap that we have been discussing today, and then we are going to formulate our response. Stay tuned!
 ST Suppl., Q. 41, Art. 1
About the Author: Bridget Groff is an M.A./Ph.D. student in the School of Philosophy at the Catholic University of America. She currently works part-time at the United States Conference of Catholic Bishops as an intern for the Subcommittee for the Promotion and Defense of Marriage.