Tuesday, August 1, 2017

Avicenna vs Turtles

Anglophone metaphysicians, and perhaps some other metaphysicians too, fairly recently started thinking about things in terms of ontological dependence. The idea is that some things depend on other things, or are grounded in those things; some facts are true in virtue of other facts, some things are fundamental while some things depend on the fundamental things, and so on. There’s a whole mess of concepts in the vicinity and we still haven’t sorted it all out, but it seemed like a useful way to think. It still does. I still think like that myself, sometimes.

One question you might ask about this framework is this:
  • Must there be a funamental level? Couldn’t it just be turtles all the way down?

Ross Cameron addressed this question in a paper a few years ago (Cameron 2008). He basically came to the conclusion that he couldn’t find anything incoherent about everything being grounded in something further down, but it’s an inelegant set-up and we should expect the world not to be like that. When I’ve come across people citing his paper it has mostly been to agree with his conclusion, although this impression may be unrepresentative or at least out of date. I like the paper too, and I’m pretty sympathetic to his take on the issue: metaphysical systems don’t have to be incoherent to be implausible.

Now, Cameron wasn’t the first person to think about this sort of thing. He mentions some predecessors in the paper, but today I’m going to talk about one he doesn’t mention. About a thousand years ago Avicenna was coming up with a proof of the existence of God, like you do, and his proof involved thinking about something structurally quite similar to the turtles question and coming to the opposite conclusion over whether there has to be something at the bottom. He thought the infinite descent scenario really was incoherent. Since one can count the people cleverer than Avicenna on the fingers of one hand, if he’s challenging our contemporary consensus we should probably take a look at what he had to say.

I’m not an Avicenna scholar, unfortunately. My knowledge of Avicenna comes mostly from a podcast by one Avicenna scholar (Adamson 2010-, especially #138-142) and a book by another (McGinnis 2010). I’ve also read a few passages from Avicenna’s own work in translation, including one on the argument I’m talking about here (McGinnis and Reisman 2007, especially pp214-5). It’s not nothing, but you probably won’t find me trying to turn this blogpost into a paper. (But if you’re an Avicenna scholar and think there’s something here worth tackling properly together, I’m not busy.) You might wonder why I’m writing about it at all, given my incompetence to do the topic justice; it’s basically because it seemed like there was something there and nobody else seemed to be writing about it. Maybe that’s because the medieval-philosophy-in-Arabic crowd and the contemporary-analytic-metaphysics crowd don’t overlap much. Anyway, if you think I’m talking rubbish but not such irredeemable rubbish as not to be worth engaging with, we can have a discussion in the comments or wherever and try to understand the issue better.

So, here’s Avicenna’s argument as I understand it.
  1. He’s got a distinction between things which are necessary through (or in) themselves and things which are necessary through another. He’s not understanding necessity the same way philosophers do nowadays - possible worlds and all that - but I wouldn’t like to try to explain exactly how he is understanding it. It seems at least to be structurally a bit like something related to our contemporary concept of ontological dependence, though.
  2. He thinks that everything is either one or the other, and nothing is both. In terms of ontological dependence, you can think about things that depend on something else, and things that don’t.
  3. He wants to show that at least one thing must be necessary in itself. He’s going to go on to argue that various things follow from something being necessary in itself, and that there can only be one such thing, and he’s going to say that this necessary existent is God. But for the moment he just wants to show that there’s at least one.
  4. We know that something exists. Look around yourself, look within yourself, whatever. Something exists.
  5. Now gather everything together that is necessary through another. If there aren’t any such things, then since something exists, something must be necessary in itself. But if there are, then gather them together into one big object. (We should resist the temptation to call this object The Great Mumkin.)
  6. Is this object necessary in itself, or through another? If it’s necessary in itself, then we’re done. If not, then what is it necessary through? (I’ve seen this step presented in different ways, and Avicenna may have presented it himself in different ways. He actually thinks it’d be absurd for the sum of all things necessary through another to be necessary in itself, but it’s worth noting that we don’t have to agree about that for his argument to work.)
  7. If it’s necessary through a part of itself, that’s either absurd or counts as the part being necessary through itself. (I’m not really sure how this step goes, and it seems to me that it’s where most of the action is.)
  8. If it’s necessary through something that isn’t part of it, then that thing must be necessary in itself, because everything else is a part of it.
  9. So whichever option we go for, something is necessary in itself.

Now, I expect I’ve garbled the argument somewhere. The bit where we say that things can’t be necessary through a part of themselves seems especially dodgy. Here’s a worry: take the sum of everything that exists. Is that necessary in itself, or through another? If anything besides God exists, then it can’t be necessary in itself, at least according to Avicenna, because he` thinks only one thing is, and that thing is God and doesn’t have proper parts. But if it’s necessary through another, then that other thing must be a part of it, because everything is. But that’s not supposed to be allowed. So I don’t really get what’s going on there. (I guess he could say that in this case we choose the option at step 7 of the part being necessary in itself. But I do think I’m missing something here.)

One way of patching this is to say that everything is either necessary in itself, or is necessary through another, or is the sum of something necessary in itself and something necessary through another. (I’m using a pretty classical-mereology framework, because Avicenna seems to be. To call Avicenna a classical mereologist would be anachronistic by 900 years or so, but the argument helps itself to principles that are accepted by classical mereology but rejected in some non-classical mereologies. If classical mereology rules out turtles all the way down, that’s interesting in itself. Investigating which mereological principles are essential to the argument and which aren’t would be interesting too, and if the argument has something in it then it’s something we should do.) If we make this assumption, the argument still goes through much the same. You just include the mixed option in step six, and note that the mixed option also entails that something is necessary in itself. The sum of all things would be the sum of the Necessary Existent, which is necessary in itself, and Creation, which is necessary through another, viz. the Necessary Existent.

With different mereological assumptions you might also try constructing the sum-of-all-dependents object by removing everything necessary in itself and taking what’s left. That relies on a complementation principle you might want to reject (but which classical mereology accepts), but it’s worth noting the option. That object might not contain all dependents - if there’s a dependent object that is part of a necessary object, for example - but if it depends on something outside itself then something is outside it, and so something is necessary in itself because everything outside it is part of the sum of things necessary in themselves.

Anyway, let’s adapt Avicenna’s argument to the question of whether everything might be dependent on something else. We’ll call things that are dependent on something else dependent, and other things independent. We’ll allow mixed cases, and assume classical mereology (though not atomicity - there could be gunky things all of whose parts have proper parts).
  1. Something exists.
  2. If there are no dependent things, something is independent and we’re done. Otherwise take the sum of all dependent things.
  3. If it’s independent or mixed, we’re done. So assume it’s dependent. What’s it dependent on?
  4. If it’s dependent on something that isn’t part of it, that thing must be independent or mixed, and we’re done.
  5. If it’s dependent on something that is part of it, that’s either absurd or counts as it being independent or mixed. (This is the dodgy step.)

In Cameron’s paper, he does sort of address a version of the summing-the-dependents objection, although not with particular reference to Avicenna. Let’s look at what he says:

Another potential justification for the intuition is familiar from the debate between Leibniz and Hume. Here, the thought is that if there could be an infinite chain of entities e1, e2, e3, ... such that e1 is ontologically dependent on e2, and e2 ontologically dependent on e3 etc, then, while every entity in the chain is grounded, nothing grounds the chain itself. Even if there needn’t be a first member of the chain – an independent entity that provides the ultimate ontological grounding for every member of the chain - there must be an ontologically independent entity to ground the existence of the chain itself.

But that’s unconvincing. Grant for the sake of argument that not only must every being on the chain have an ontological grounding but the chain itself must have an ontological grounding. This doesn’t entail that anything is an independent entity. Perhaps the chain of entities e1, e2, e3, ... depends on a further entity ea1 which depends on ea2, which depends on ea3 etc? And if someone asks “but what about the chain ea1, ea2, ea3...?” we can appeal to a new entity eb1 which is the ontological ground of this new chain, and which depends on eb2 which depends on eb3 etc. And so on. In each case, the infinite chain of entities is dependent on an entity which is itself the first member of another infinite chain. Provided we’re prepared to postulate more and more entities, one for every cardinal number, then nothing will go ungrounded. (Cameron 2008: 11)

I don’t think this works against of Avicenna’s version of the objection. The problem is that mereology isn’t like set theory. (The reference to “one for every cardinal number” is talking about the way set theory deals with this kind of thing.) In set theory you can’t just gather all the things of a certain kind into a set and ask questions about it. You get Russell’s paradox and others if you allow that. But in mereology you can gather all the dependents together into a sum and ask questions about it. You don’t get the paradoxes, and in fact accepting unrestricted mereological composition is fairly popular among people who work on the topic. (The difference basically arises because the set of all Xs can’t have members that aren’t Xs, but the sum of all Xs can have parts that aren’t Xs. For example, the sum of all cars has parts that are wheels, not cars.) Since mereology allows this kind of comprehension principle, it doesn’t help to postulate more and more entities as Cameron suggests. Anything you postulate will either be part of the sum-of-all-dependents already or won’t be a dependent. There are issues about infinite extensibility and unrestricted quantification which might apply here, but our understanding of that is much less settled than our understanding of set theory, and moving from the difficulties of unrestricted quantification to the impossibility of unrestricted composition is a leap that would need some heavy-duty justification. I think it’s fair to say that in light of Avicenna’s version of the argument, Cameron hasn’t really said enough here to fend off the objection.

So I guess bringing Avicenna into the debate wasn’t a complete waste of time. But might there be something else wrong with Avicenna’s argument? The argument looks pretty solid, at least given the assumptions about mereology, except for the step at the end. Why shouldn’t an object be dependent on something that’s part of it? There are a couple of structures we can imagine as challenges to Avicenna’s picture.

  • Gunk: everything is dependent on its proper parts taken together, and everything has proper parts. So everything is dependent on something.
  • Turtles: reality is made of the earth sitting on top of an infinite descending series of turtles. Everything is dependent on the sum of the things its parts depend on, and everything is dependent on any segment of the series unbounded below and wholly strictly lower than it, if any. So the earth is dependent on the sum of the turtles, the top turtle is dependent on the sum of the other turtles, and the whole of reality is dependent on the sum of the turtles but not on itself (since nothing depends on the earth), and the sum of the turtles is dependent on the sum of the turtles other than the top one. (There are some issues to go into about overdetermination, joint dependence and so on, but I think it should be possible to fill in these details in this general picture.)
    • If you prefer, you can work with Simple Turtles: reality is a mereologically simple earth above a (not densely ordered) infinite descending series of mereologically simple turtles. Everything depends on the sum of everything strictly below its top part.

That wasn’t so hard. What was Avicenna thinking? Three possibilities come to mind:
  • He had a notion of necessity-in-itself which rules out these structures.
  • He had a notion which doesn’t rule out these structures but he didn’t think of them.
  • He had a notion which doesn’t rule out these structures but had other substantive commitments that do.

All are prima facie plausible, though the second is uncharitable. Avicenna scholars will have views, but I’m not in a position to say what those views would be. But we can still think about how we should respond to these cases.

It’s worth taking the gunk and turtle cases separately. With gunk I think the best thing to do is just admit defeat if we’re allowing that things can depend on their proper parts. I think composition is identity, and things don’t depend on their parts: things are their parts. (Gunk is a bit weird if composition is identity, but I don’t see that it’s incoherent. Indeed, I don’t see that you couldn’t have gunky pluralities even if composition isn’t identity. Regular readers will be familiar with gunky pluralities from the previous post.) If you don’t think composition is identity - and if you’ve worked in the area then you probably don’t - then you might adopt some other substantive commitment linking mereology and dependence, like saying if an object depends on a part of x it depends on x, and so if things depended on their parts they would depend on themselves, which tends not to be allowed. But if you think things can depend on their parts, I guess you’re welcome to think the gunk example undermines the Avicennan argument. (And Avicenna does seem to think things depend in some way on their proper parts, which is part of why the necessary existent can’t have proper parts. I definitely feel like I’m missing something.)

With Turtles and Simple Turtles there isn’t really a ready-made metaphysical thesis like composition as identity that I can wheel out to undermine the argument. So what can we say? Well, I don’t have a great answer, but I do think that even being able to ask the question moves the debate forward a bit in terms of where you can apply pressure. The problem Cameron had with turtles all the way down was that it’s theoretically uneconomical: you can’t have one base explaining everything, because the base needs a separate explanation, and so on forever. It’s inelegant. But now we have a different objection: Turtles isn’t just inelegant; it’s weird. And where there’s weirdness, there might be Rationally Compelling Metaphysically Necessary Principles to rule it out. If you can think of one, feel free to put it in the comments.


  • Adamson, Peter (2010-present): The History of Philosophy Without Any Gaps. Podcast. Historyofphilosophy.net.
  • Cameron, Ross P. (2008). Turtles all the way down: Regress, priority and fundamentality. Philosophical Quarterly 58 (230):1-14.
  • McGinnis, Jon (2010). Avicenna. Oxford University Press.
  • McGinnis, Jon & Reisman, David C. (eds.) (2007). Classical Arabic Philosophy: An Anthology of Sources. Hackett.

Thursday, July 27, 2017

Gunky Pluralities

Philosophers have been squeezed out of most traditional areas of physics by fancy scientists with their “experiments” and their “research budgets”, but one thing they’ve managed to cling on to is mereology. We’ve even reclassified it as metaphysics so the physicists won’t accidentally stumble across it when looking for a book on something more important. Mereology is the theory of parts and wholes. Mereologists try to answer questions like these:
  • Is there a great big object which all the other objects are parts of?
  • When x is part of y, is there always another object z which is the rest of y?
  • Does anything even have proper parts? (A proper part of x is a part of x that isn’t x itself.)
  • Could there be two different objects made out of the same parts at the same time?
  • Could there be something all of whose parts had multiple parts?

The last question is about gunk. I wrote here once before about gunk, when describing an argument by David Hume against the possibility of gunk. You have to be a little bit careful when defining gunk, because what seem like equivalent definitions might not be equivalent if you accept some other exotic principles about parthood, or at least reject some mundane ones. One fairly careful definition of gunk would be “something all of whose parts have proper parts”, but that doesn’t really get at what we had in mind if we allow that things can be proper parts of each other.

Now, parts and wholes aren’t the only game in town when it comes to gathering objects together. Somebody once told me that Bolzano identified like fifteen different ways of gathering objects together. Maybe it wasn’t fifteen, but I’m pretty sure it was a lot. Although perhaps this person was pulling my leg.

Anyway, one alternative to making a whole out of some objects is to make a plurality out of them. A broom is an object made of a brush and a handle. A brush and a handle are a plurality whose members are a brush and a handle. (Sets are different again; two things form a set, but they are a plurality.) Now, you might think that there’s no distinction here: a broom just is a brush and a handle. If that’s what you think then I’m actually on your side, but most people who work on this stuff don’t think that’s right. (One person who works on this stuff and thinks it is right is Meg Wallace, of whose work on both this and other things I am a fan.) The mainstream view is that a broom can’t be a brush and a handle, because (apart from anything else) a broom is one thing and a brush and a handle are two things. Anyway, let’s make the distinction.

It turns out that a lot of the candidate principles governing wholes and their parts are analogous to candidate principles governing pluralities and their subpluralities. Let’s say that Tom and Harry are among Tom, Dick and Harry. Let’s also say that Tom is among Tom, Dick and Harry, and that Tom, Dick and Harry are among Tom, Dick and Harry, but not properly among them. And let's allow that "some things, the xs, are F" can be true even if only one thing is F, so some things are (each!) Buzz Aldrin. Now we have a language in which to ask similar questions about pluralities and subpluralities to the ones we asked about parts and wholes.
  • Are there some things, the xs, such that whenever there are some things they’re among the xs?
  • When the xs are among the ys, are there always some things, the zs, that are the rest of the ys?
  • Are any things properly among any other things?
  • Could there be some things, the xs and the ys, such that any things among the xs were also among the ys and vice versa, but the xs weren’t the ys?
  • Could there be some things, the xs, such that whenever some things the ys were among the xs there were some things, the zs, properly among the ys?

Call some xs that fit the definition in the last question a gunky plurality. Could you have gunky pluralities? Are they ridiculous? I asked Twitter if they were ridiculous, and the eight respondents were evenly split on the matter.

Gunky pluralities twitter poll results.png
Am I an experimental philosopher yet?

I was a little bit surprised. I think gunky pluralities are coherent, but in the past I’ve never detected much enthusiasm for them. While a Twitter poll with eight respondents doesn’t give much of an indication of the frequency of a position among any population apart from the people who responded to it, I was quite surprised to see that four people, not including me, saw the tweet who don’t think gunky pluralities are ridiculous. Maybe they didn’t understand the question. I did phrase it in terms of membership instead of in terms of amongness, but if anything I’d expect that to make the position seem more ridiculous, not less.

Now, I’m invested in gunky pluralities being coherent because I think composition’s identity and amongness is parthood, and so if gunky pluralities are incoherent then gunk is incoherent, and nobody wants to be committed to that. (Someone with a fancy research budget might come along and make a fool of you.) But even if you don’t think composition’s identity, and I suppose even if you don’t think merelogical gunk is possible, you can still make sense of the question about gunky pluralities. Are they ridiculous or aren’t they?

I think that Hume and Leibniz probably took the view that they were ridiculous. Hume may well have been thinking only about mereological gunk, and I’m pretty sure Leibniz was, but it would have been kind of weird to endorse their arguments for the mereological case and not the analogous arguments for the pluralities case. It’s possible of course that they didn’t really see a distinction, Bolzano not having arrived on the scene until the following century. Hume credited his argument to a Monsieur Malezieu, who I guess is probably this guy, although his English Wikipedia article could use some work and his French one doesn't mention Hume. Here are some quotes for you:

It is evident, that existence in itself belongs only to unity, and is never applicable to number, but on account of the unites, of which the number is composed. Twenty men may be said to exist; but it is only because one, two, three, four, &c. are existent, and if you deny the existence of the latter, that of the former falls of course. It is therefore utterly absurd to suppose any number to exist, and yet deny the existence of unites; [...]
But the unity, which can exist alone, and whose existence is necessary to that of all number, is of another kind, and must be perfectly indivisible, and incapable of being resolved into any lesser unity. (Hume, Treatise on Human Nature, 1.2.2)

And there must be simple substances, since there are compounds; for a compound is nothing but a collection or aggregatum of simple things. (Leibniz, Monadology, translated by Robert Latta, proposition 2)

It’s also true that our language gets a bit strained when we try to talk in a way that never presupposes that the thing we’re referring to is just one thing. You’ll have noticed that when I was trying to do it earlier. On the other hand, there doesn’t seem to be any reason you can’t construct a logic that can accommodate gunky pluralities. You might struggle to get a model theory in terms of sets that didn’t make a certain kind of person a bit grumpy, but this kind of person is already grumpy about variable-domain model theory for modal logic, so you’ll be in good company. (It may be that their grumpiness is warranted, but my impression is that even if the objection in the case of modal logic succeeds, the analogous objection would be question-begging in the case of gunky pluralities. But I’m pretty open to being wrong about that.) One possibility is that the idea of gunky pluralities is one of those things that’s ridiculous without being incoherent. I don’t really get what the problem is supposed to be, though. If you think they’re ridiculous, and it seems at least four of you do, let me know why in the comments!

Sunday, July 23, 2017

Four Ways To Misuse Words

There are lots of ways to misuse words. Today I’m only going to talk about four. I’m interested in the situation that occasionally arises with emotionally or politically charged terms. It’s been happening for a long time with “terrorist”, we all watched it happen over the last year or two with “fake news”, and yesterday I heard someone say that it’s happening with “gaslighting”, although I haven’t noticed that one myself. Sometimes people talk about the phenomenon by saying “when people say [word] what they really mean is [concept]”. Here the concept is not what you’d expect a dictionary to say the word meant; it’s the concept that applies to the things these people in fact apply the word to. For example:
  • ‘When people say “terrorist” what they really mean is “enemy combatant”.’
  • ‘When people say “fake news” what they really mean is “news unfavourable to me”.’
  • ‘When people say “gaslighting” what they really mean is “saying things I don’t agree with”.’

I don’t think this is usually the best way of putting it, and I think it obscures the distinction between at least four ways of misusing words.

Ignorance: The word conventionally means one thing, but I use it to mean something else, because I’m mistaken about the convention. For example, if I thought that “cat” meant what “octopus” means, and so I said “cats live underwater and have eight tentacles”. Or I might think that “fake news” meant what “untrue news” means, and use the term “fake news” to describe any news story I don’t think is true.

Lying: I know what concept the word conventionally expresses, but I use it for things that concept doesn’t apply to because I want to mislead people. For example, I might want people to think that cats live underwater and have eight tentacles, and so I’d say “cats live underwater and have eight tentacles”. Or a news story might come out which wasn’t favourable to me, and so I’d mislead people into thinking it was deliberately made up by saying “that’s fake news”.

Bullshit: I don’t really care what the word means, and I may not know what it means, but I do think that it’d be rhetorically advantageous to apply the word to it so I go ahead and do it. For example, I might have heard people calling stories “fake news” and getting some rhetorical mileage out of it, so I call stories I don’t like “fake news” as well.

Inflation/Defining Down: I know that using the word for something stretches the conventions governing the word without necessarily breaking them, but I use the word anyway because I want people to categorize it with the central cases. For example, I might refer to something as fake news when it was really a result of a combination of sloppy reporting and wishful thinking, because I want people to lump the reporter in with people who deliberately make stories up.

There’s probably some overlap here, and one kind of use might shade into another. But I think only the first one is properly a case of using a word when what you really mean is something else. Maybe, when people say “when people say X they just mean Y” they’re usually being metaphorical and just mean “when people say X it just means Y”. But maybe not. And there’s a difference between what someone means by a word and what you can infer from the fact they’re using the word. I don’t think people who talk this way always have that distinction clearly in mind. It’s a pretty fuzzy distinction in a lot of cases, so that’d be understandable, but the distinction’s there. I think in at least some cases this is part of the irksome tendency on the part of a certain kind of person to attribute all the ills of the world to the imprecise use of language.

Saturday, July 15, 2017

A Load Of Rubbish

A crash of rhinos. A parliament of owls. I’m not above leafing through a book of miscellaneous lists once in a while, and such books occasionally have a list of collective nouns. I’ve got views about collective nouns.

Sometimes a collective noun will have become a word in one of the normal ways, and it will be used when people aren’t actually talking about collective nouns, and competence in speaking the language involves knowing what it’s used for. A certain kind of social grouping among lions is called a pride, and a different kind of grouping among ants is called a colony. If you call the lions a colony and the ants a pride then you’re making a linguistic mistake. I’m not sure exactly what kind of mistake it is. I think it’s probably a worse mistake than if you talked about a swarm of sheep or a flock of bees. It’s more or less just unidiomatic to talk about a swarm of sheep, but an ant colony really isn’t a pride. Maybe I’m being too harsh or not harsh enough on one of these kinds of mistake, but the point is that they’re mistakes. You’re flouting the conventions internalized by competent language users if you talk about a pride of ants, unless something very odd is going on.

Anyway, that’s not what a lot of collective nouns are like. Basically what happens is this. People know that there are collective nouns for some things, like lions, ants and bees. Glossing over the fact that a pride of lions isn’t just any old group of lions gathered into the same place at the same time, they notice that lots of things don’t have collective nouns. So they make them up. They make suggestions that are supposed to be fitting or satirical or simply euphonious, and congratulate each other when someone comes up with a good one. It’s a parlour game. As an extension of the parlour game, people will sometimes propose more or less comprehensive lists of the things. They don’t usually catch on, of course. The parlour game produces proposals for established usages, not established usages. Perhaps “murder of crows” is one that caught on. But usually they don’t catch on.

Now, part of the parlour game is that it begins with someone asking “what’s the collective noun for a group of lions/larks/ostriches?” If it was lions, someone could rightly say “a pride of lions”, and they’d be right. That is the established word for a kind of group of lions. You only move to phase two of the parlour game, where people make proposals, if you can’t come up with an answer at phase one. And one thing you might do in phase one is try to look it up. To meet this need, people make lists and put them in the kind of miscellany books I talked about at the beginning of the post. Now, a scrupulous listmaker would do what lexicographers do: look at established usage and see if there is a collective noun being used for a group of ostriches. If there used to be but it’s out of fashion, they’ll let you know it’s archaic or worse. And if there’s never been an established term for a group of ostriches, they don’t put one in the list. Alternatively, the listmaker could piggy-back on the efforts of a scrupulous lexicographer by looking through a dictionary written by one.

But our listmakers are not scrupulous. They want a nice long list with nice funny entries. Unfamiliar entries. So instead of looking at established usage or the records of it found in dictionaries, they copy the lists of proposals made by people who wanted to play the parlour game but had no friends to play it with. I once heard that there was a vogue at one point for sending such lists to magazines, though I don’t know if this is true. So now we have two kinds of lists. Lists of proposals which someone might send in to a magazine as an extension of a parlour game, and the plagiarized lists of lies that turn up in miscellany books.

Now, I know what you’re thinking. We’re all descriptivists now, and in the case of language, when a lie is repeated often enough it becomes the truth. I don’t know if that’s what we ought to say or not. So in the interests of science, I’ll look up “parliament”, “crash” and “exaltation” in the OED, to see if they give a usage meaning a group of owls, rhinos or larks respectively. I’m excited!

Parliament: it does mention “a parliament of owls” as an example of this extended usage:
Parliament definition owls OED.png
The usage of “a parliament of owls” they give is from a book called An Exaltation of Larks by James Lipton, which is of course a book about collective nouns. (There may be nothing objectionable about the book. I haven’t read it, and as you can see I don’t have a problem with all instances of people writing about collective nouns.) Note that in the definition the OED gives there’s nothing that makes “parliament” any more appropriate to owls than to larks, and it’s less appropriate to either than to rooks, which the lists invariably say come in murders.

Crash: the entry doesn’t mention rhinos at all.

Exaltation: here’s the screenshot so you can judge for yourself:
Exaltation larks definition OED.png
I too can judge for myself, and I’d point out that the OED’s authors have not found any usages which were clearly not in the context of discussing collective nouns, and they also appear to think that the established way of referring to such a group of larks is as a flight. But of course A Flight Of Larks would not have been a good title for James Lipton’s book.

(The entry for “pride”, of course, has a definition as “A group of lions forming a social unit,” and gives several examples of it being used outside the context of discussing collective nouns. It says it’s an extended usage, but that’s probably accurate.)

So the scrupulous lexicographers at the OED present us with a bit of a mixed bag. A parliament can be a group of birds but isn’t specific to owls. A crash of rhinos isn’t a thing. An exaltation of larks is a thing but not to my mind a very honourable one, though your mileage may vary.

Now, up until recently I had the very negative attitude towards this whole collective noun nonsense that astute readers will have detected in the foregoing. However, the other day I saw some medievalists playing the parlour game on Twitter - they were still on a high from a conference in Leeds, where I live, and wanted a collective noun for medievalists - and I must say it seemed like fairly harmless fun. So I don’t know what to think. I guess if all you’re doing is making suggestions, that’s fine. And if you make a really good suggestion at the right time, say you’re at a medievalist conference and you think of a good one for a group of medievalists, then it might end up as an established term like “pride” or “colony”. That's fine too. But don’t make lists of lies, and certainly don’t go correcting someone when they call a group of rhinos a colloquium just because you read somewhere that we’re supposed to call it a crash.