Language separates humans from all the other animals on this planet. Birds may have their songs, bees may wobble their bottoms, but none of them can match us when it comes to describing the difference between a coffee cup, a runny nose and the theory of relativity. We have evolved language, a wonderfully complex system for manipulating, storing, retrieving and sharing meaningful symbols. Human language has given birth to human civilisation and all that we have achieved as a species, for better or for worse, over the past 50,000 years.  

Naming things, abstract or concrete, is a form of categorisation, but it is important to remember that our categories say more about the categoriser than the categorised. This need not be problematic if the difference is trivial. The philosopher Wittgenstein showed how words are fundamentally and necessarily imprecise; every effort to use a word to describe something and communicate it to another, is in some senses doomed to failure, because it can only be an approximation generated from that person’s individual experience of that word in his or her world.

Problems really begin, however, when the terms that we use to describe and classify our world go beyond the philosophical into the domain of suffering. Pain, illness, death and dying are hard to dismiss lightly. When it comes to talking about disease, we need to keep our misunderstandings to a minimum.

For the past 5,000 years, from the medical writings of the Hindu Ayurvedas, via the works of Hippocrates, Galen and the great Islamic physicians of the first millennium to Sydendham and Virchow, doctors have known the importance of recognising a disease and giving it a name. The word we use for this is diagnosis. The etymology of the word tells us that diagnosing something is much more than simply naming it. Dia implies an embracing of the entire of something, whereas gnosis roughly translates as the concept of knowing. Diagnosis, then, is what we do when we are moving deeper into the heart of something rather than simply naming it.