Ans: “Ode to a Nightingale” is a celebrated poem by John Keats who is a remarkable figure in the galaxy of romantic poets. This very poem is a great product of the fertile imaginations and of contrast between the world of man and that of the nightingale, between the world of reality and that of unreality, between impermanence and permanence.

The first stanza presents the contrast between the feeling of the poet and that of the nightingale. The poet feels very sad to hear the sweet song of the nightingale. This song brings him excessive joy. In its excess, the joy turns into joyous pain. He thinks his power of sensation is getting benumbed. Contrary to this unhappy mood of the poet, the happiness of the nightingale is conveyed through its sweet song in the following lines:

“That thou light-winged Dryad of the trees
In some melodious plot
Of beechen green and shadows numberless
Singes of summer in full-throated ease.”

At the very outset of the poem, the poet is so intoxicated by the melodious song of the nightingale that he glorifies the bird and associates it with images that it creates in his mind. He longs for various means to enter a dream-like state that reflects another worldly experience. He wants to leave the real world because it is full of harsh, grim realities. The melody of the nightingale’s song makes him think of the discord, struggles, and despair of the age in which he lives and contrasts the chaos of men’s actual life with the content and peace prevailing eternally in nature. In the actual world, youth grows pale too soon and finds his eternal abode in the grave. Here each and every moment is full of sorrow and grief. Beauty fades in no time and the passion of youthful lovers has only a short duration:

“Where youth grows pale and spectre-thin and dies
Where but to think is to be full of sorrow.”

But the ideal world of the nightingale is the complete opposite. It is free from the pain and suffering, diseases and decay and death that human beings are subject to. The poet contrasts the transience of the individual life with the permanence of the songbird’s life. Throughout the poem, there is an opposition created between the realm of the nightingale and that of the speaker. The speaker is shown to live amid time and decay whereas the nightingale lives in an eternal realm:

“The voice I hear this passing night was heard
In ancient days by emperor and clown.”

Going to the world of the nightingale with the help of imagination the poet wants to die in the midst of flowers. He thinks if he can die in the world of Nightingale his death will be a richer one.

Though the poet has made a striking contrast between the human world and the world of the nightingale, he could not live forever in the world of the nightingale. He had to return to this real world at last—

“Forlorn! The very word is like a bell
To toll me back from thee to my sole self
Adieu! The fancy cannot cheat so well
As she is famed to do deceiving elf.”

So, we can say that this is how John Keats has contrasted the world of mankind with that of the Nightingale in “Ode to a Nightingale”.