約翰·濟慈（JohnKeats，1795年—1821年），出生于18世紀末年的倫敦，他是杰出的英詩作家之一，也是浪漫派的主要成員。

To J. H. Reynolds Teignmouth, May 3rd 1818

My dear Reynolds;

What I complain of is that I have been in so an uneasy a state of mind as not to be fit to write to an invalid. I cannot write to any length under a disguised feeling. I should have loaded you with an addition of gloom, which I am sure you do not want. I am now thank God in a humour to give you a good groats worth—for Tom, after a Night without a wink of sleep, and overburdened with fever, has got up after a refreshing day sleep, and is better than he has been for a long time; and you I trust have been again round the Common without any effect but refreshment.

An extensive knowledge is needful to thinking people—it takes away the heat and fever; and helps, by widening speculation, to ease the Burden of the Mystery; a thing I begin to understand a little, and which weighed upon you in the most gloomy and true sentence in your letter. The difference of high sensations with and without knowledge appears to me this—in the latter case we are falling continually ten thousand fathoms deep and being blown up again without wings and with all the horror of a bare shouldered creature—in the former case, our shoulders are fledge, and we go thro’ the same air and space without fear.

It is impossible to know how far knowledge will console us for the death of a friend and the ill ‘that flesh is heir to.

I compare human life to a large Mansion of many apartments, two of which I can only describe, the doors of the rest being as yet shut upon me—The first we step into we call the infant or thoughtless Chamber, in which we remain as long as we do not think—We remain there a long while, and notwithstanding the doors of the second Chamber remain wide open, showing a bright appearance, we care not to hasten to it; but are at length imperceptibly impelled by the awakening of the thinking principle—within us—we no sooner get into the second Chamber, which I shall call the Chamber of Maiden-Thought, than we become intoxicated with the light and the atmosphere, we see nothing but pleasant wonders, and think of delaying there for ever in delight: However among the effects this breathing is father of is that tremendous one of sharpening one’s vision into the heart and nature of Man—of convincing ones nerves that the World is full and misery and heartbreak, pain, sickness and oppression—whereby This Chamber of Maiden thought becomes gradually darkened and at the same time on all sides of it many doors are set upon—but all dark—all leading to dark passages—We see not the balance of good and evil. We are in a mist—We are now in that state—We feel ‘the burden of the Mystery,’ To this point was Wordsworth come, as far as I can conceive when he wrote ‘Tintern Abbey’ and it seems to me that his Genius is explorative of those dark Passages. Now if we live, and go on thinking, we too shall explore them.

Your affectionate friend
John Keats