If you hang around certain sectors of the Catholic blogsphere much, you probably hear from time to time about this thing called "formal causality" that some people wish could get a little more respect. However, if you're not in the habit of reading Aristotelians or Thomists in your spare time, you may not be sure what is meant by it.
First of all, the word "causality" will lead you astray. In standard parlance "cause" is generally used in terms of "cause and effect". However, Aristotle's four causes (material, efficient, formal and final) cover a rather wider stretch of ground.
According to Aristotle's way of thinking, the universe is made of up matter and form. Matter in and of itself is just stuff. (If Star Trek had been written by Aristotelians, they would have constantly encountered beings with made up of matter and animate souls but no form -- the Aristotelian version of The Blob.)
Say you have a coffee mug sitting next to you (mine is already empty). That mug is made of matter. It also conforms to the 'form' of mugness. The form consists of those essential elements of mugness that make a mug be a mug, instead of a tumbler or a cocktail glass or what-have-you. So the material cause (the stuffness) of my mug is ceramic and glaze. The formal cause of my mug (the form) is 'mugness' -- whatever that is.
Now why, you may be wondering, do people feel this is such an important thing to consider? It sounds almost like a tautology. (This mug is a mug because it is like a mug.) Well, form may not seem much of a big deal when you're dealing with a mug. Indeed, I think one is right to question whether there really is an ideal form of "mug" or if mug is simply a human invented category which is useful in sorting the contents of your kitchen cupboard. However, form becomes very important when considering certain moral questions.
A couple years back, I was discussing gay marriage with an earnestly liberal Christian who was also a medical doctor. She asserted that the existence of hermaphrodites proved that gender was a loose set of descriptive categories, and therefore one should marry whomever one felt attracted to. I claimed that humans were meant to be males or females capable of reproduction, and that the fact that some people are born without clear or functioning gender characteristics no more meant that people were not supposed to mate male on female than the fact that some people are born blind means that people are not supposed to be able to see. The fact that there are deviations from the norm does not mean that a norm does not exist. After some consideration, she said that concepts lick sickness, disability and disfunction were all relative to arbitrary ideas of how a human "ought" to work, and that now she thought about it she could think of no objective definition of "health" vs. "sickness" for human beings. Awkward predicament for a doctor, eh?
The defect in this doctor's thinking was that she had discounted any idea of there being a "form" to which we as humans are meant to conform. And having dispensed with the idea of form, she no longer could say anything was actually a defect.
Now, when we start speaking of "defects" in regards to people, it's important to be clear on what we mean. From the point of view of Catholic morality, there is an inherent dignity to the human person by virtue of identity -- by the mere fact that it is a human person. The dignity of the person does not stem from the degree to which it conforms to the ideal. Someone who is born blind is not less of a human because he lacks a characteristic which humans are meant to have. Nor is a hermaphrodite less of a human because he lacks correctly formed gender features.
Further, there are some characteristics which pertain to the human form, and others which are merely accidents (surface features that do not pertain to the essence of what it is to be human). So while we might say that it is in the essence of a human to have eyes capable of sight, there is not particular value to a certain color of eyes.
Formal causality (like most of Aristotle) isn't taught much these days. Yet, as you can see, it's necessary to be able to make any kind of sane analysis of what a person, thing or animal is, and what it is supposed to be.
Many point to the predominance of science in the modern mind as the reason why few people understand formal causality anymore. And yet, in a sense, modern science should give us a good, realistic grounding in at least certain kinds of formal causality, though because of its limitations it clearly doesn't place a particular moral value on conforming to form.
Take, for instance, the question of hermaphrodism which my acquaintance brought up. From a biological point of view, it's clear that an individual who has unformed or malformed gender attributes, and thus is incapable of or uninterested in reproduction, is in some sense not the way an individual is supposed to be. After all, if all individuals were that way, there wouldn't be any more. It's an evolutionary dead end. However good one might feel about being a hermaphrodite, or how affection one might have for him/her, it's clear that from a biological point of view something isn't right in that picture. Although biology doesn't produce moral precepts, it's at least clear that hermaphrodism cannot be considered 'normal' and thus perhaps it's a bad idea to use it as the basis for your moral analysis.
Certainly, modern science doesn't concern itself with questions like "what is the essence of being human" but there is a certain rough realism about it which, if taken seriously, should help to reign in the wilder impulses of our modern, relativistic, moral feel-good-ism.
[this post originally written in Feb, 2006]