periadventitial and adventitious and adventitial

"Peri," the Greek preposition meaning "around," is an incredibly rich source of English words that are generally unknown or only known in very specific communities. As is so often the case in investigating words, however, one word leads to others until we have a veritable intellectual and sensual feast. We might get through two in this essay; probably only one.

Periadventitial

The Century defines something periadvential as "situated on the outside of the adventitia, or outer coat of a blood-vessel." Something that is adventitious is "of the nature of an addition from without; extrinsically added, not essentially inherent; supervenient, accidental, casual." From 1751 we have: "Our Thames..is tainted with an infinite variety of adventitious bodies from the streets." In Sartor Resartus (1831), Carlyle could say: "When a man first strips himself of adventitious wrappages; and sees indeed that he is naked.." The word adventitious also found a usage in the English common law, dating back to the 17th century. Chambers defines the use of the term in law in 1751: "Adventitious, in the Civil Law, is applied to such goods as fall to a man, either by mere fortune, or by the liberality of a stranger, or by collateral, not direct succession. In this sense the word stands opposed to Profectitious; by which are signified such goods as descend in a direct line." Ain't law grand? It always wants to divide the world into categories.

With this as background we can understand the meaning of adventitia as a "membranous structure, usually morbid, covering but not belonging to an organ." The adjectival form of the word is adventitial, which means the same thing as adventitious. From 1652: "Neither doth nature prefer any creature for its adventitials or accidentals." An interesting quotation from 1633 almost invites further investigation. Thomas Adams' exposition of 2 Peter 3:5 has: "There be three degrees of ignorance.. Secondly, adventitial, which is accompanied by actual sin." I would hazard a guess to say that his first category is actual sin but I don't know how he further divides his hamartiological world.

Thus, though the term adventitial can be used in theology, its most prevalent usage today is, not unexpectedly, in medicine. For example, there is online an abstract of a paper entitled "Adventitial myxofibroblastoma." I will let you find it on your own if you are so inclined.

A Philosophical Issue

But here I think I have a little problem. I can illustrate it by quoting from the Wikipedia article on adventitia. It says that adventitia "is the outermost connective tissue covering of any organ, vessel, or other structure. For example, the connective tissue that surrounds an artery is called the adventitia because it is considered extraneous to the artery." Then it provides a graphic of the tunica adventitia, which surrounds the tunica media, and is the outermost layer of the blood vessel. But in what sense can we call it adventitious or unnecessary? In what sense is it "not essentially inherent?" In fact, what inheres in what? Is the skin of an apple adventitious? An orange skin? A banana peel? Or is it only "extrinsic" in the sense that it is outermost? The concept of adventitiousness suggests something that isn't really essential to the being or item being described.

But, the older I get the less I really understand what is essential and what might be inessential. I had always believed that it was essential that one get one's taxes in on April 15, but once I developed a wider network of friends I began to see how an April 15 date for submission of taxes was only a sort of target date. If they missed it, well, there was always August or October. Thus, what was in my judgment essential had evolved to being adventitious. Well, why can't you do that with almost everything else in life? What is, for example, a university? It obviously is not to be associated with any one person, essential as they appear to be for the success of the place, since the university lasts far longer than any one of its professors or presidents. But, is it the buildings? You would be hard pressed to say that any one building is essential to a college. Thus, by pressing the issue gently, we begin to see how adventitious life is. Herotodus might be famous for positing the notion that life is chancy; I will bring him up to date by saying that life is, primarily, adventitious.

Returning to Periadventitial

Come to think of it, then, if something adventitial is inessential, something periadventitial is something that surrounds or lies around the thing that is not essential. So, now we have two degrees of separation from what some might consider "the real." It really makes us wonder about our concepts of reality.

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