Taxing taxonomy: how easy is it to categorise words?
Look around the room you are in right now. What do you see? Probably nothing out of the ordinary. You will see all kinds of objects, large and small with different shapes, sizes and colours. If you are in a bedroom you’ll see a bed, a wardrobe and perhaps one or more chairs. On the bed there will be one or more pillows and a duvet or blankets. If you are in a kitchen, you might see a sink with a tap, a stove, a table and perhaps a washing machine. You’ll seldom think of this consciously, but all the objects around us belong to categories. In the home such categories include ‘furniture’ (chair, bed, desk, sofa), ‘bedding’ (pillow, duvet, blanket), ‘appliances’ (kettle, fridge, microwave), and so on. You can think of these categories as pigeon holes, as in the image below:
Philosophical thinking about the notion ‘category’ goes right back to the ancient Greek philosophers. Aristotle set up particular categories on the basis of their characteristics, and he thought of them as sharply bounded, as in the image. He also argued that all the members of a particular category are equally representative of that category. The Aristotelian way of looking at categories was very influential. A famous taxonomy of the natural world was proposed by the Swedish botanist Carolus Linnaeus in his Systema Naturae (1735). He divided the ‘Kingdom of Animals’ into six classes: mammals, birds, amphibians, fish, insects and worms, each of which was typified by a set of unique characteristics. It is perhaps not surprising that Aristotle’s views were so long-lasting, because his way of thinking allows us human beings to make sense of the world around us.
However, in recent decades scholars have argued that the Aristotelian system is perhaps a bit strict. For example, the philosopher Ludwig Wittgenstein (1889-1951) mused about the notion of ‘game’ in his Philosophical Investigations (1953), and noticed that it is not so easy to define. Think about it for a moment. Do games involve winning and losing? Are they always entertaining? Are they played by more than one person? He decided that it is impossible to define games in an Aristotelian way by enumerating a number of characteristics that must apply to all of them. Instead, he said, games bear ‘family resemblances’ to each other, much like when members of a family have a similar-looking ears, share eye colour, etc.
Psychologists have also wondered about the way we should view categories and concluded that within them we should perhaps recognise prototypical members and peripheral members. For example, within the category of birds we have prototypical birds such as sparrows and red robins, and less typical birds such as penguins and ostriches. As you will know, the latter can’t fly.
What does all this have to do with grammatical categories, you may be wondering? Well, in grammar, we also use all sorts of categories, such as noun, adjective, verb, phrase, clause, etc. When we describe the grammar of a language these categories are useful, because they help us understand how it is structured. In many grammar books the grammatical categories are seen in an Aristotelian way by regarding all their members as being equally representative. But is this the right way to view them?
Within the class of verbs, take the words eat and must. Are they equally typical members of their class? Arguably, this isn’t the case. Wouldn’t it be reasonable to say that just as a sparrow is a more typical bird than a penguin, eat is a more verby verb than must? The reason is that eat behaves grammatically more like a verb than must, as becomes clear from the following examples:
He eats his breakfast on the bus. They ate all their sandwiches within a few minutes. She was eating nuts throughout the film.
As you can see, eat can take a third person –s ending, can occur in the past tense and in the progressive construction. But none of these are possible for must.
All the examples below are ungrammatical:
*He musts leave early tomorrow. *She musted have seen this. *They are musting to send their CV.
So we see that particular words can be more or less typical representatives of their grammatical categories. Perhaps this is not surprising. After all, language is a natural phenomenon and life shows us there are always exceptions to the rules.
(This blog first appeared on the Macmillan International Higher Education blog.)