A month or so ago I saw an academic talk with the inciendiary title, “Aristotle’s Worst Idea”. It concerned the notion of “monotelism” in Aristotle, a word the speaker had coined to express Aristotle’s judgement that things which had a single purpose are superior to those with many purposes. This principle, that a thing out have a single function, has imperfect application both in nature and artifacts – Aristotle admits to examples in both techne (craft) and phusis (nature) where a thing has more than one function, but this is always unfortunate, always either because the maker (in the case of craft) was lazy, or because mother nature found it too difficult to make a species with a single thing for each function.
The idea as he expressed it frustrated me because it seems correct (it is after all based on quite extensive textual evidence form Aristotle), but it seems to bypass any philosophical questions that might be raised concerning monotelism. Practicing philosophy as beginning from definitions, giving examples, comparing with other philosophers, and giving examples of how the philosophical idea had technical or cultural rammifications seems to completely avoiding any “philosophizing” at all – everything done here under the name “philosophy” would be better called either science or cultural anthropology.
The philosophical question, it seems to me, is “What is a function/telos?” In other words, what does it mean to say something has a purpose, a role, an end? To give the simple Aristotelian answer: the Final cause is one of the four causes, and it is the purpose for which a thing is made, the function which that thing will play which is the reason to bother making it at all. For example, the final cause of a religious artifact is the role it plays in a cultural ceremony – it is for the sake of this role that it will play that it is made in the first place.
But this so far has avoided the question, I have not defined function qua function but rather function qua principle, or qua cause. What does it mean to say something has a function? I present an artifact for consideration:

A swiss army knife is what Aristotle, or at least the presenter on Aristotle, would characterize as an object made by a lazy craftsperson: he has saved time and sacrificed perfection by making a single thing which has many roles. Perhaps because of this he will not have to make as many things? This does not seem important, even if it might be true in a pre-capitalist economy. What is crucial seems to be whether this understanding is true at all – is it true that the knife has many functions?
Again, we must return to what it means for something to have a function. Imagine you are packing for a camping trip, and you are deciding which things to bring. Certainly you’d want to bring several shirts, because they will get dirty. But perhaps also they will be used as a pillow. And if no towels are brought, shirts might be used to towel off after a dip in the lake. So it might seem that a shirt has no single “function” but simply a plethora of possible functions, some seen in advanced and considered, and some not (every good woodsman knows how to find new uses(functions) for things in the bush – its perhaps in this sense that we can say the woodsman is the opposite of the mechanic, for whom it is never a virtue to use the “wrong tool for the job”). But none of this intuitively convinces me that a shirt doesn’t have a function – it seems that a shirts function is simply not expressible as a determinate proposition, rather it is something intangible, it is something like the grasp I have on what it will be used for, and I have this grasp on the “functions” of the shirt as a whole, and that is the function of the shirt. Said otherwise, it appears that the function of the shirt is not its particular uses but its usefullness as such, its sense of being “full of use value”.
Arriving at the swiss knife, I wish to defend the honour of the knife against the charge that it is less perfect than a more traditional hunter’s knife simply because it has many functions. It seems that to say a hunter’s knife has “one function” and a swiss knife has “many functions” is to use the term “one” equivocally. Certainly one admits that a Hunter’s knife can be used in many ways – for example, to skin a Fish or a Deer, to prepare tinder for a fire, etc… Perhaps a hunting knife could even be used in a religious ceremony – in fact I believe something analogous to this is actually the case in Boy Scouts. When one tosses a hunting knife in one’s pack, it is already aimed at a variety of possible “functions”, deemed in advance to be useful in a set of situations which cannot be entirely known in advance. This does not seem to be any different from a Swiss Knife, which perhaps has many functions in a more explicit manner, but it seems wrong to suppose these functions have less unity than the functions of the hunting knife. Again, I can toss a Swiss Knife in my pack, and the choice to do so can be based on a rough grasp of what situations I might encounter and what the knife might come in useful for. To answer why this grasp is of a grouping of situations “as a whole”, the answer is just the factual unity of the object – the fact I can’t simply throw in half the knife without breaking it and loosing all its usefulness.
The preliminary conclusion I have arrived at is that a things “function” is not expressible in a proposition in advance because it is best characterized as my perception of its telic/final cause – the set of purposes it might play in situations which I anticipate. The “monotelism” of a thing is just the unity of its functions, the fact that they can be grasped as a whole, and this follows from it being one thing and not many. The argument against codifiable monotelism is that any account of a “single” purpose can be given again as many or multiple purposes, depending on how specifically one characeterizes the situation in which that purpose is fullfilled.

