What is it to know what a thing is? Suppose I can identify a laurel tree by its smell, but not by the shape and colour of its leaves. Or the other way around. Do I know what a laurel tree is in each of these cases? Or suppose I am a scientist and can identify it by analysing its genome, but not by its smell nor by the shape and colour of the leaves... Suppose I know only or, on the contrary, do not know the uses people give to laurel leaves. How many properties of laurel must I know so that I can know what laurel is? I think I must know something, otherwise I wouldn't even know what the word"laurel" means. But what? It can't be just one small thing: I wouldn't say that I know what laurel is if I can identify it only by its smell.