This is one of my all time favourite passages of literary criticism. John Carey on why Shakespeare was better than Marlowe and why “imagination-stirring indistinctness” is the root of great literature:

‘Shakespeare’s superior indistinctness can easily be seen if we compare the way Marlowe’s Barabas, and Shakespeare’s Shylock, talk about their wealth.

Here is Barabas:

“Bags of fiery opals, sapphires, amethysts,

Jacinth, hard topaz, grass-green emeralds,

Beauteous rubies, sparkling diamonds … “

[I i 25–7]

And so on. Pretty good, you will say. Yes, it is. But it is not very indistinct, so the imagination has not much to do. You can easily picture bags of jewels. Of course, even Marlowe’s lines are beyond the reach of visual arts like painting or photography. You cannot paint grass-green emeralds, except by some ponderous device like juxtaposing painted grass and painted emeralds, whereas language can merge the two in a flash. Painting cannot manage metaphor, which is the gateway to the subconscious, and that hugely limits it by comparison with literature. True, there is Surrealist painting, but it is static and deliberate, and quite unlike the flickering, inconsequential nature of thought. However, with all due credit to Marlowe’s jewels, compare Shakespeare’s Shylock when he hears that his daughter (who has run off with her lover, taking some of her father’s gold and jewels with her) is living it up in Genoa and has exchanged a ring for a monkey.

“Thou torturest me Tubal, – it was my turquoise, I had it of Leah when I was a bachelor: I would not have given it for a wilderness of monkeys”. [III i 1I2]

Marlowe could never have written that. Quite apart from the human depth, the indistinctness is what stamps it as Shakespeare’s. ‘A wilderness of monkeys’, the lightning phrase with which Shylock registers his wit, scorn and outrage, is unforgettable and unimaginable – or, rather, imaginable in an infinite number of ways. How do you imagine it? Are there trees and grass in the wilderness? Or just monkeys? Are they mixed monkeys, or all of one kind? With tails or without? Of what colour? What are they doing? Or are these questions too demanding? Is the impression you get much more fleeting, much less distinguishable from the mere blur of total indistinctness? At all events, compared to ‘grass-green emeralds’, ‘a wilderness of monkeys’ is a wilderness of possibilities. We are tempted to say that it is a ‘vivid’ phrase, and it is understandable that we should want to use that word about it. But ‘vivid’ is often used to describe clear-cut effects, such as a bright pattern or colour composition, and Shakespeare’s phrase is not vivid in that way, rather the opposite. It manages to be at once vivid and nebulous. It is brilliantly and unfathomably indistinct, which is why the imagination is gripped by it and cannot leave it alone.’