Do you do ‘do’, or don’t you?

I’m sure you haven’t missed that Sabina recently started a series about the early Germanic languages on this blog? The series will continue in a couple of weeks (you can read the latest post here), but as a short recap: when we talk about the modern Germanic languages, these include English (and Scots), Dutch (and Flemish), German, Icelandic, Faroese, and the mainland Scandinavian languages (Swedish, Norwegian, and Danish). These languages, of course, also have a plethora of dialectal variation under their belts1. Today, I’m gonna tell you about one particular grammatical feature that we find in only a couple of Germanic languages. You see, when it comes to the grammar of the modern Germanic languages, they’re all relatively similar, but one quirky trait sets the ones spoken on the British Isles apart from the rest: do-support.

Before we begin, I want to clarify my terminology: Do-support is a feature of syntax, which means that it’s to do with word order and agreement. The syntax concerns itself with what is grammatical in a descriptive way, not what we prefer in a prescriptive way2. So, when I say something is (un-)grammatical in this post, I mean that it is (dis-)allowed in the syntax.

So what is do-support?

Take a simple sentence like ‘I like cheese’. If a speaker of a non-English (or Scots) Germanic language were to turn that sentence into a question, it would look something like ‘Like you cheese?’, and in most Germanic varieties a (clearly deranged) person who is not fond of cheese would answer this with ‘No, I like not cheese’. In their frustration, the person who asked may shout ‘Eat not cheese then!’ at the deranged person.

But, those sentences look weird in English, both the question and the negative sentence. The weirdness does not only arise from the meaning of these sentence (who doesn’t like cheese?), but they’re, in fact, ungrammatical!

English, and most Scots dialects, require do-support in such sentences:

  • Do you like cheese?
  • No, I do not (or, don’t) like cheese.
  • Don’t eat cheese then!’

The above examples of do-support, interrogative (the question), negative declarative (the negated sentence), and negative imperative (the command) are unique to English and Scots, but there are other environments where do is used, and where we also may find it in other Germanic languages, such as:

  • Tag-questions: ‘You like cheese, don’t you/do you?’
  • Ellipsis: ‘I ate cheese yesterday, and Theo did (so) today’
  • Emphasis: ‘I do like cheese!’
  • Main verb use: ‘I did/am doing a school project on do-support

In all the examples above except for the emphasis and main verb usage, do is essentially meaningless; it doesn’t add any meaningful (semantic) information to the sentence. Therefore, we usually call it a “dummy” auxiliary, or simply dummy do.
(Auxiliary is the name for those little verbs, like do, is, and have, which come before other verbs in a sentence, such as in ‘she is eating cheese’ and ‘I have eaten cheese’)

English and Scots didn’t always have do-support, and sentences like ‘I like not cheese’ used to be completely grammatical. We start to see do-support appearing in English around the 15th century, and in the 16th century for Scots. As is the case with language change, do-support didn’t become the mandatory construction overnight; in both languages we see a period where sentences with and without do-support are used variably which lasts for centuries before do-support eventually wins out (in the 18th-19th century).

Interestingly, in this period of change we also see do-support in non-negated sentences which aren’t intended to be emphatic, looking like: ‘I do like cheese’. These constructions never fully catch on though, and the rise and fall of this affirmative declarative do has been called a “failed change”.

It’s ok, affirmative declarative do, you’ve still contributed greatly to do-support research!

Why did we start using do-support, though?

Well, we aren’t exactly sure yet, but there are theories. Many scholars believe that this is a so-called language-internal development, meaning that this feature developed in English without influence from another language. This is based on that do used to be a causative verb in English (like cause, and make in ‘I made Theo eat cheese’), which became used so frequently that it started to lose its causative meaning and finally became a dummy auxiliary. This process, where a word gradually loses its meaning and gains a purely grammatical function, is called grammaticalisation.

There have also been suggestions that it was contact with Welsh that introduced do-support into English, since Welsh had a similar structure. This account is often met with scepticism, one reason being that we see very little influence from any celtic language, Welsh included, on English and Scots grammar in general. However, new evidence is regularly brought forward to argue this account, and the origin of do-support is by no means a closed chapter in historical linguistics research.

What we do know is that do-support came about in the same time period when English started to use auxiliaries more overall – you may have noticed that, in English, we’re more likely to say ‘I am running to the shop’ than ‘I run to the shop’, the latter being more common for other Germanic languages. So, we can at least fairly safely say that the rise of do-support was part of a greater change of an increased use of auxiliaries overall.

The humble dummy do has baffled historical linguists for generations, and this particular HLC writer has been trying to understand do-support in English and Scots for the past few years, and will most likely continue to do so for a good while longer. Wish me luck!

Footnotes

1I’ve written about the complex matter of language vs. dialect before, here.

2In our very first post on this blog, Riccardo wrote about descriptivism and prescriptivism. Read it here for a recap!

Fun Etymology Tuesday – Spirits

And we’re back, with yet another Fun Etymology! Today’s word is “spirits” (in the alcoholic sense of the word).

The word itself comes from Anglo-French spirit, Old French espirit, from Latin spiritus, meaning a breathing (both respiration and of the wind, breath and breath of god. From this Latin root, we also get spirit (meaning the soul or a ghost), of course, which is related with a bunch of other sayings (like being in “high spirit”). The Latin root is related to Latin spirare, meaning “to breathe”, perhaps from PIE *(s)peis-, meaning “to blow” (which, btw, is the source of Old Church Slavonic pisto, meaning to play on the flute).

So, how did we get from breathing to liquor? Well, from the late 14th century, this word started to be used in alchemy, meaning a “volatile substance” or “distillate”, and from c. 1500 as “substance capable of uniting the fixer and the volatile elements of the philosopher’s stone”. Sound kinda Harry Potter-y right? Anyway, this led to spirits meaning a “volatile substance”, a meaning that became semantically narrowed to “strong alcoholic liquor” by the 1670s.

A pretty long trip from it’s “original” meaning and it’s modern, wouldn’t you say?

Welcome back next week!

Early Germanic Dialects – Let’s get going!

Willkommen zurück, everyone! (I have no idea if you would actually say that in German but we’ll stick to it!)

You might remember that we, three weeks ago, kicked off a new little series by introducing you a little bit to Proto-Germanic? Well, this series is called Early Germanic Dialects (coincidentally, this is also the name of a course on this particular topic that we took during our studies), and in it, we will be introducing you a little bit to – you guessed it – the early Germanic dialects!

Before we study those, though, we need to talk to you a bit about the relationship of these dialects. We’re sure you remember that we’ve talked quite a lot about the concept of ‘families’ of languages (Germanic, Italic, Finno-Ugric, etc.). Today, we’ll look closer at the Germanic language family!

So, of course you know by now that the Germanic languages are languages that comes from Proto-Germanic (which, in turn, hails from Proto-Indo-European). What you may not know (or at least we haven’t outright told you) is that the Germanic language family is also divided into different branches, three in total. These are: West Germanic, North Germanic and East Germanic.

East Germanic, unfortunately, had only one known descendent and that language has gone extinct: Gothic. We know that Gothic once existed and we have a pretty good idea about what it looked like because of a few surviving texts. One of the most recognised of these is the so-called Codex Argenteus, a beautiful 6th century manuscript which contains a 4th century gothic translation of the Bible. Known most commonly as the Silver Bible or the Silver Book, the manuscript is an impressive sight: its thin vellum pages are stained a regal purple, the script and illuminations are made in silver and gold with an ornate jewelled binding. Sorry, I got a bit carried away there, but truly, it’s quite remarkable. If you ever find yourself in Stockholm, Sweden, make a bit of a detour and see it IRL at the University of Uppsala, its current home.

Anyway, back to linguistics. So, Gothic is the only descendent of East Germanic, meaning, of course, that there are currently no living descendents of East Germanic. That is not the case for the other two branches though. Let’s look at North Germanic first.

The North Germanic branch of the tree are the languages that come from Old Norse, meaning, of course, the Viking languages!

Kidding (kind of). The languages that comes from Old Norse are Icelandic, Faroese, Norwegian, Danish and Swedish. These languages share a couple of features which are not found in most of the East and West Germanic languages, such as u-umlaut (though you may see u-umlaut in other Germanic languages, such as Old English, too, but it is commonly more limited than the u-umlaut found in Old Norse and not to be confused with the ‘umlauted’ vowel Ü in German).
You’ve heard us talk about umlaut before, quite a bit actually, but we’ve primarily focused on i-umlaut. U-umlaut works in a very similar fashion: when a /u/ or a /w/ followed in the next syllable, stressed vowels were rounded so instead of milk, as in English, you get mjòlk (Icelandic), mjölk (Swedish), for example. Of course, there are important differences within these languages too, but we’ll get there in due time.

Now, the West Germanic branch is a bit bigger than East and North. This branch consists of all languages that comes from Anglo-Frisian, that is Old English and Old Frisian, and the languages that comes from Proto-German (not to be confused with Proto-Germanic), that is Old High German, which eventually produced German and Yiddish, as well as all languages that comes from Old Low German, also known as Old Saxon and Old Dutch, which eventually became Low German, Dutch and Afrikaans.

Let’s put that in a tree for you:

This makes it a bit easier to visualize, of course, but this way of representing things have shown to be somewhat problematic. As you may notice, for example, it gives you no indication of timeline, and of course, all of the language changes that makes West Germanic different from North or East Germanic didn’t happen at the same time. Consider the tree, if you will, an extremely simplified visualization of a very complex relationship.  

This post has aimed to give you some insight into the relationship of the Germanic languages, but we will end on another note of caution: this relationship is far from uncontroversial. For example, there are some features shared by the Anglo-Frisian languages and the North Germanic languages but not by the Proto-German languages, and there are some features shared by Old High German and Gothic that set them apart from the other languages – some have even gone so far as to claim that English is a North Germanic language, not a West Germanic one.  This, of course, indicates a closer relationship than what is readily evident by the traditional tree that you see here.

So, keep this with you, always: don’t accept the tree as the unequivocal truth, because really, it’s not.  

via GIPHY

References

Our primary reference for this post is:

Robinson, Orrin W. 1992. Old English and its closest relatives. London: Routledge.

If you would like to know more about the Silver Bible, check it out at the University of Uppsala

And if you would like to know more about the claim that English is actually a North Germanic language, check out Emonds and Faarlund’s book English: The language of the Vikings, published in 2014. Fair warning though: the hypothesis has been questioned by many voices in the historical linguistic community and we suggest you also check out a couple of reviews on the book to get an understanding of both schools of thought. We will not be discussing our personal thoughts on this topic here, but if you want to know more and discuss it with us, just send us an email or ask us a question on Facebook or Twitter.

Fun Etymology Tuesday – Liquor

FunEty-time!

Today’s word is “liquor”. Coming to English during the Middle English period from Old French licor, from Latin liquorem (in nominative form becoming liquor), which originally came from the word liquere, this little word is an excellent example of a semantic language change known as “semantic narrowing”.
You see, the Latin form liquorem could indicate a liquid, liquor, wine or even the sea! The older Latin form liquere simply meant “be fluid, liquid” so it didn’t necessarily indicate something containing alcohol. The narrowed sense caught on quickly though, and roughly 100 years (c1300) after the word itself was first recorded, the narrowed meaning of some fermented or distilled drink shows up. By the 18th century, the broader sense that the word originally had appears to have become obsolete and we’re left with a much more limited meaning. Such language changes are quite common in languages as they evolve, and we’ll definitely see more of them in coming FunEties, but in the meantime, enjoy the fact that “As long as liquor is in him” was a Middle English expression, “as long as he is alive”.

Welcome back next week!

There be language change afoot–but why?

We’ve written about several big, historic sound changes, like umlaut and Grimm’s Law. But why does pronunciation have to change at all? Why can’t it just stay the same forever? Surely, that would be easier for everyone (especially us historical linguists trying to reconstruct speech from a time before sound recording).

Without diving in too deep today, let’s look at two of the big forces playing tug-o’-war with our phonemes (and the rest of our language): good, old-fashioned laziness and the need to be understood.

I called the first force laziness, but perhaps a kinder appellation would be “conservation of energy.” Unless you live by yourself in a cottage deep in some leafy forest somewhere, you probably regularly do a fair amount of communication (yes, even you introverts). Speech1 is a repetitive motion, and like other repetitive motions (e.g. signing your name), we unconsciously streamline it as it sinks deeper and deeper into our muscle memory. ‘Cannot’ in most instances becomes ‘can’t’; the <tt> in ‘button’ becomes [ʔ] instead of [t].2

This tendency to expend the least amount of effort in language production is called ease of articulation. This is what leads to phenomena like umlaut: it’s easier to pronounce consecutive vowels in the same area of the mouth, so back vowels are pulled forward after front vowels (e.g. Proto-Germanic *mūsiz “mice” becomes OE *mȳs). Similarly, vowels in unstressed syllables tend to relax into schwa. Why enunciate every sound when you don’t really have to? (Except sometimes you do have to.)

Ease of articulation is one thing, but on the other hand, language can’t allow itself to devolve into a mushy, mumbly mess. That would be self-defeating. When your whole purpose in life is to communicate messages, by gum! you’ve got to make sure you can effectively communicate a message. If things become too similar, a language finds ways to self correct, to dissimilate. Dissimilation is a process whereby two linguistic elements that are confusingly alike are pulled back apart to a reasonable, comprehensible distance. Take, for example, the OE pronouns “he” and hēo “she”. Linguists aren’t exactly sure which specific sound change stepped in to shift  hēo to she, but I think we can all agree that it’s easier to tell who’s who with more distinct pronouns. Or in another case, we find the word pilgrim ultimately comes from Latin peregrinus “foreigner, traveler”. In Latin words with far too many /r/s, one of them commonly became an /l/ over time to unmuddy the waters.

Though they seem almost like an uptight, mothering older sister (dissimilation) and her carefree, lackadaisical little brother (ease of articulation), these two processes work in tandem as much as they work against each other. You could almost say they bring balance to the Force. (But you could also say that languages are wild, organic things that refuse to be tied down. It’s not you, it’s them. And as you may have guessed, ease of articulation and dissimilation aren’t the only suspects complicating this situation. We’ll get there.)

Notes

1 It’s something we haven’t brought to the forefront in a while, but I’d like to remind you that when we talk about “speech,” we could just as well be talking about signing. Sign languages function much like spoken languages.
2 Depending on your dialect.

Fun Etymology Tuesday – Alcohol

Aaaand it’s Tuesday again! I’ll admit, I enjoy doing your FunEty every week, it is such an interesting way to learn more stuff! I hope that you agree!

Let’s talk “alcohol”! This word came to English during the early 15th century as “alcofol”, meaning any very fine powder! This word comes from Latin alcohol, meaning the powdered ore of antimony, ‫but‬ ultimately derived from Arabic ‫اَلْكُحْل‬‎ “al-kuhl” which was the metallic powder used to darken the eyelids! “Al-“ is the definite article “the” in Arabic and “kuhl” comes from the Arabic word “kahala”, meaning to stain or paint.

By the late 17th century, alcohol was used in English to mean the pure spirit of anything, including liquids, but we have to wait all the way until 1753 before it is first recorded to mean the intoxicating ingredient in strong liquor, which was then extended to meaning the intoxicating element in fermented liquors!

Goodness, that’s quite a trip! Join us next time when we look a bit closer at the word liquor, which doesn’t always (or at least didn’t always) refer to alcoholic drinks. Welcome back!

Did the Southern Hemisphere Englishes develop from Cockney?

Remember two weeks ago, when I said that I’d get back to you about Southern Hemisphere Englishes? Well, I’m following through with this post!1

So, what do I mean by Southern Hemisphere (SH) Englishes? Well, it can be defined more broadly or more narrowly, but for this post I mean varieties of English that are spoken as a first language in the Southern Hemisphere, such as in Australia, New Zealand, South Africa, St Helena, and the Falkland Islands. Today, I will focus on the first three varieties on that list: Australian English, New Zealand English, and South African English.

Public domain map from https://ian.macky.net/pat/index.html

If you, like me, enjoy listening to accents, imitating them, and trying to figure out their characteristics, you may have noticed that these three SH varieties often sound very similar2. With Australian and New Zealand English, them being geographical neighbours could partly explain this, but this does not work as an explanation for South African English. Also, there is not great dialectal variation within these varieties, relative to, for example, the UK, where you get distinct accents and dialects between two places only a commuter’s distance apart. How can this be?

In my post about American English I went a little bit into how the development of that variety is affected by the linguistic diversity of the input (that is, what English accents and dialects were spoken by settlers), challenging the claim that American English would be a preserved Shakespearean English. The story of the formation of SH Englishes is, unsurprisingly, not so different from this. Once again I want to investigate the idea that a language develops in a straight line from one single older language, and the question of the week is therefore: Is Cockney to blame for the similarities between SH Englishes?

The SH countries in question were colonised by Britain much later than North America was, but in the same century as each other; the 19th century. The nature of their settlement differed slightly, however: Australia was at first a penal colony, New Zealand was initially settled by craftsmen, labourers, and farmers, and in South Africa, which was previously colonised by the Dutch, a deliberate action was made to start British farming communities by sending out 5000 British settlers to start this up (this did not work very well, and the British settlers soon moved into the cities to take on other professions).

Now, let me tell you a little bit about Cockney:

Famous fictional Cockney speaker: Eliza Doolittle, in George Bernard Shaw’s Pygmalion (perhaps more known from the stage musical adaption My Fair Lady)

Famous non-fictional Cockney speaker: Michael Caine (an actor who, depending on your age, you either know from the movie Alfie, or as Alfred in Christopher Nolan’s Batman trilogy)

Famously bad attempts at Cockney: America’s Next Top Model season 4 acting challenge

Cockney is the accent traditionally spoken in London’s West End, which, in the 19th and early 20th century, was one of the more impoverished areas of London. The Southern English accent spoken in the West End developed in a quite distinct way, influenced in part by the culturally diverse population which resided there. If you’re not from Britain, you may recognise Cockney as the accent often used to make fun of/imitate the British. Some notable Cockney features are, for example: pronouncing the diphthong in words like ‘mate’ so that it sounds like the diphthong in ‘might’, dropping word-initial /h/ so that  ‘hello’ becomes ‘ello’, vocalising (= turning into a vowel) the /l/ in certain environments so that ‘milk’ sounds like ‘miwk’, and glottalising the /t/-sound between vowels so that words like ‘glottal’ become something like ‘glo-al’. The cockney accent also had more general South-Eastern English features (and indeed, some of the already mentioned features are also found elsewhere), such as not being rhotic (so that ‘far’ is pronounced ‘fah’), and raising of the ‘e’-vowels to sound more like ‘i’, making ‘better’ sound more like ‘bitter’.

During the 20th century, the rise of the prestigious Received Pronounciation (RP)3 meant that Cockney became more and more seen as vulgar and overall unprestigious. However, Cockney speakers were large in numbers, and, as is often the case in language change, features from Cockney have successively found their way into wider South-Eastern British English and even RP – so much so that the traditional RP known as the Queen’s English sounds much more “common” these days, even when spoken by the Queen herself.

From a British perspective, Cockney and monocles don’t exactly go hand in hand

Cockney is frequently given credit for the Australian English accent, and this is not an entirely bonkers idea. In a situation such as the settlement of Australia and New Zealand, the number of speakers of a certain variety, i.e. the frequency of certain accent features, has been said to play a greater role than the social prestige of a variety, and the majority of convicts arriving in Australia were Cockney speakers. The interaction between the convicts, and thus the numerical influence of Cockney features over other accents, started already on the ships taking them to Australia, and once there, the speech of the convicts even affected the speech of the penal officers. Thus, Cockney speech features became numerically dominant in Australia and shaped the way English was spoken there.

We know already that the type of settlement was different in New Zealand, so what role did Cockney play there? Well, Cockney speakers in New Zealand were not as many as in Australia, but there were significant numbers of speakers from the South-East of England (about half of the settlers). There were also many settlers from Scotland, and a smaller but relevant number of settlers from Australia (7%)4, in the early days of New Zealand settlement. So, even though Cockney specifically wasn’t spoken by great numbers in New Zealand, those features of Cockney which were also found in other Southern English and (Cockney-influenced) Australian accents spoken in New Zealand had numerical strength among the settlers there. Therefore, these features, such as the high ‘e’ in better, non-rhoticity, and the distinct diphthong in mate, eventually became features of New Zealand English.

Likewise, the British settlers in South Africa were largely from the South-East of England. While the number of settlers was quite small in South Africa, they formed a tight-knit community of English-speakers in a region where many other languages were spoken, Dutch/Afrikaans being only one of them, and largely resisted influence from these other languages. Thus, even though the group of English-speakers in South Africa was small in numbers compared to the rest of the South African population, it was the majority accent within the English-speaking community, i.e. South-Eastern British English, which came to influence the development of South African English.

The numerical strength of individual features, rather than the “whole accent”, is important to understand why some notable cockney characteristics, such as h-dropping and t-glottaling, are missing from all of these SH accents. New Zealand, for example, had plenty of input from other British accents than South-Eastern ones, so pronouncing  /h/ and /t/ was more common among speakers than not doing so. Australia was also subsequently settled by speakers of different English varieties, which we can assume swamped out some of the features more specific to Cockney.

So, can we blame Cockney entirely for the similarities between the different SH varieties? Of course, which I hope to have shown in this post, it is never that simple.

Footnotes
1 The content of this post is again largely credited to material by Dr. Claire Cowie at the University of Edinburgh. I also recommend this video for a general (albeit slightly dated) overview of Cockney and Australian English.
2 Of course, a more trained ear than mine will hear clear differences between them. If you’re not very  familiar with these accents, listen to some samples from the International Dialects of English Archives (IDEA):Australian English, New Zealand English, South African English.
I picked three samples that were similar in that they were all by men in their 20s. There are more samples to listen to on the IDEA site (and many many more accents!).
3 We’ve mentioned RP before, for example here in the context of standardisation.
4 As a reminder, I’m getting these numbers from material put together by Dr. Claire Cowie for the course LEL2C: English in Time and Space at the University of Edinburgh.

Fun Etymology Tuesday – Berserk

It’s Tuesday! Again! Where does the time go? You may or may not have noticed that the HLC website was down earlier today but don’t fret! It’s up and running again, working as smoothly as ever, though we went a bit berserk when we realised that it was down.

Speaking of berserk, it’s our word of the day!

This word, though you might think it an early arrival to the English language (I mean, Vikings were around quite early on) actually wasn’t introduced in English until the mid-19th century, by the legendary Scottish poet Sir Walter Scott who used the word “berserkar”, reportedly believing that it came from Old Norse “berr”, meaning bare or naked, and “serkr”, meaning shirt.

Scott thus seems to have believed that it meant something like “warrior who fights without armour” though, while that may or may not be true, the word is more likely to hail from Old Norse “berserkr”, meaning a raging warrior of superhuman strength.

This Old Norse word is ultimately a compounded form of Proto-Germanic *ber-, meaning bear, and “serkr”, thus literally meaning “a warrior clothed in bear skin” (and perhaps insinuating the power of a bear, though that’s conjecture on our part).

Welcome back next week!

Noam Chomsky – Patron Saint of March, 2019

Happy March dear followers!
As per tradition, it is time to present this month’s Patron Saint: Professor Noam Chomsky.
Professor Chomsky, who celebrated his 90th birthday in December, is an American linguist who has become somewhat of a legend in our field – he is often referred to as the “father of modern linguistics”. Furthermore, he is usually that one linguist that non-linguists know about (apart from possibly Tolkien, but then people don’t usually know that Tolkien was a linguist).

Chomsky’s fame outside of linguistics is usually due to his political and philosophical writings. His political views, which align with libertarian socialism and anarcho-syndicalism, have often been a subject of controversy, especially in his home country. However, today we want to tell you about what made him famous as a linguist; Chomsky developed the theories of generative grammar, Universal Grammar, and the Chomsky hierarchy. A facebook post does not hold enough space for us to tell you all about these, but the most significant part of Chomsky’s theories is this:

In the 60s, Chomsky departed from the then commonly held view that the brain was a blank slate and language was wholly learned from the surroundings, and instead suggested that we are all born with an innate knowledge of language, that this knowledge is the same for all humans, that the innate grammar holds the same rules for all, and that children only need to learn the small differences in settings of the rules which are specific to the language in the input – thus the concept of Universal Grammar was born. Since the 90s, Chomsky has been developing his ‘Minimalist Program’, which aims to formalise grammar using as few rules as possible, with a greater focus on how the brain makes decisions about the grammar it is given from the input.

Chomsky’s framework is heavily based in biology and cognitive sciences, placing the field of linguistics within these sciences for the first time, which is one reason why his work is considered to have revolutionised the way we perform linguistic research to this day. Chomsky’s theories are still praised and scrutinised, followed and discarded. His frameworks still divide linguists into two camps; are you for or against generative grammar? Regardless of sides, no one can argue the impact of Chomsky’s theories on the field of linguistics, both for the subsequent work that aimed to prove his theories, and the work that aimed to disprove them.