I

   I saw a dead man's finer part
Shining within each faithful heart
Of those bereft. Then said I: "This must be
   His immortality."

II

   I looked there as the seasons wore,
And still his soul continuously upbore
Its life in theirs. But less its shine excelled
   Than when I first beheld.

III

   His fellow-yearsmen passed, and then
In later hearts I looked for him again;
And found him--shrunk, alas! into a thin
   And spectral mannikin.

IV

   Lastly I ask--now old and chill -
If aught of him remain unperished still;
And find, in me alone, a feeble spark,
   Dying amid the dark.

Thomas Hardy

http://www.poemhunter.com/poem/his-immortality/