Aristotle chose to open his Categories with a definition of equivocal. The example he gave was a real man and a figure in a picture. He said they can both lay claim to the name ‘animal’.
The real man, I can understand. A physical being can be called an animal. But what of a drawing or painting of a real man. Is that truly an animal or a picture of an animal?
True we talk about the man in the picture does this or that. But is that not just a representation of something where that representation is in itself a thing other than the real being it represents?
I suspect Aristotle knew the difference between a real man and a representation of a real man. It is interesting that the concept is left at this one instance in the entire text. Making a loose connection, I also suspect equivocal is a kind of reply to his teacher, Plato. It is a reminder that Plato had taught that innate ideas (eidos) were the real things and physical objects are their mere shadows. This reversal is counterintuitive. That countless examples of real objects may be what gives us the prototypes may explain just as well where our ideas and our definitions of a category comes from. And if we take Occam’s Razor to the task then the latter may be a better explanatory fit.
In the end, we know the difference between a real animal and a picture of it. Let us start here.