Simile and metaphor are essential to the emotional tone in Prufrock. In particular, Eliot`s use of simile is influenced by his study of the Metaphysical conceit, and understanding of how the Metaphysical Poets blended religious and philosophical ideas with sensuous imagery through figures of comparison. It should be noted that most of the extended comparisons in the poem are metaphors rather than similes.

‘When the evening is spread out against the sky
Like a patient etherised upon a table;’

The comparison creates a feeling of the modern city as half way between life and death, and background not to the vital connection with the earth and fertility one finds in the country, but to the impotent longings of the neurotic and indecisive Prufrock.<

`’No! I am not Prince Hamlet, nor was meant to be;
Am an attendant lord, one that will do
To swell a progress, start a scene or two,
Advise the prince; no doubt, an easy tool,
Deferential, glad to be of use,
Politic, cautious, and meticulous;
Full of high sentence, but a bit obtuse;
At times, indeed, almost ridiculous—
Almost, at times, the Fool.’

Although no explicit `like`or ‘as’ is used, making this an extended metaphor it does bear the same structural function as the epic simile or conceit. The contrast with Hamlet brings forward that even Prufrock`s indecisiveness is diminished and trivial.