RECURSION
was a thing I enjoyed a lot learning about when I started learning to code in the University of Oslo some time in the late 1970s. Functions that could call themselves were on the same level as other impulses I’d been receiving from popular culture at the time (music, science fiction, surrealistic humour). We started out learning Fortran, and we had to cheat quite a bit to achieve anything close to recursion, but then we progressed to Simula, which had in-built recursion.
One main requirement for these recursive functions was having an exit criterion, otherwise they would crash the CPU. We were fed some strong stories about students who had held up the whole faculty sharing time on the CPU, and I took a lot of care avoiding such traps as long as I worked on such a time-sharing system. When I started programming at home, I used control C a few times in order to stop endless loops, but mostly not related to recursion. At home I didn’t have Simula or anything else that could recurse. I’ve been doing some Pascal, some Basic, some Javascript. But lately I’ve toyed a little with Smalltalk, which can do recursion.
Later I learnt that recursion wasn’t specific to computer technology. Functions calling themselves are only a special case. Mathematical or linguistic recursion is not “real” recursion from a coding perspective. But mathematicians or linguists do not agree, I guess. And serial or multi-level functionality is interesting in itself, I think.
Linguistically, recursion is when one and the same statement has more than one verbal phrase. Such phrases have a verb at its core, a term of action. The rest of the phrase is there to inform on how the action is done and who or what is doing it and/or who or what it is being done upon. The phrases are strung together using conjunctions, prepositions and other such small words, ‘that’ or ‘which’ being especially prominent small words useful for recursion. We can have such examples as “he said that she could not come” or “it was an orange cat that tore down the flower pot”. Statements having more than one action and subordinate clauses of various kinds. My own introduction to the examples here is a third level of recursion.
Get Lars Finsen’s stories in your inbox
Join Medium for free to get updates from this writer.
This is common to all languages, or at least all languages that we normally come across in our lifetimes. Because of this, some people have theorised that language relies on a universal apparatus enshrined in our genes and built into the brains we grow up with. The mastery of such a complex thing as language by anyone from Trump supporters to quantum physicists shows that it has to be ingrained in us, doesn’t it?
However, these linguistic theorists are not uncommonly thought of as a bunch of f***ing b***ards, and not a few will do what they can to tear down their theoretical constructions. Some have gone as far as to penetrate the jungles of Brazil to stay for months or years with the Pirahã people, whose language is said to be non-recursive. Really? If so, they cannot phrase such common concepts as the ones I quoted above. Possibly the Pirahã have other ways to express such things or they’ve played tricks on those self-sacrificing linguistic students in some way.
Another hobby of mine is constructing languages. My first and the most developed experiment is Urianian, starting in the 1960s. Another, more recent, is Naledi, a non-recursive language. Literary language is full of recursion. The longer the sentences, the more recursion and the closer the author is to the Nobel prize. Hence, books have been published by authors mad enough to abolish full stops completely. I think of this as a little deceitful — tying full sentences together using an ‘and’ or similar doesn’t really make them more recursive (nor does tying them together with m-dashes for that matter). Ancient languages like Latin or Gaulish often did away with usual subordinate clauses and used participles or other ways to turn verbs into nouns in order to include more than one action in their statements. But this doesn’t make them any less recursive according to the theorists. Often these participles have as many adverbs or adjectives describing the actions as regular clauses, not to mention objects of the actions.
Common oral language is not very recursive. Often we communicate our sentiments using simple non-recursive phrases, sometimes we include one recursion level. Any more and it feels unnatural, or literary so to speak. Some cultures are more literary than others. For example, some Irish peasants that travellers came across in the 1800s, surprised the travellers with the complexity of their language. Or maybe those peasants were former upper class displaced by Englishmen? In my youth in the 1970s, I sometimes watched theatre broadcasts on the TV. I thought they were boring, and the most boring were the ones written by Finnish authors. When they contained any dialogue at all, its recursion level was non-existent. After moving to the countryside in my 40s, I haven’t been doing a lot of mowing. Mostly mowing is done by machines nowadays. But when they did this kind of work by hand, I imagine any communicative need that would arise would be easily fulfilled with one or few syllable words and simple non-recursive sentences.
And my experiements with Naledi show that there is no limit to the complexity or recursivity of thoughts that still can be expressed with non-recursive phrases. Though it does take an effort. If an orange cat pulls down a flower pot, you can express the idea in two sentences, one describing the colour of the cat and another what it does to the flower pot. Maybe this is how they do it in Pirahã, that is, if they didn’t just play tricks with the students. Maybe being able to think about two or more actions at the same time wholly explains why we are the only human species left alive on the planet today, or maybe not.
