Laudator Temporis Acti

Brewer's Dictionary of Modern Phrase & Fable, 2nd ed. by John Ayto and Ian Crofton (Weidenfeld & Nicolson: 2007), under dead man walking, p. 194 (via Google Book Search):

In the United States, an announcement called out by a prison guard as he escorts a condemned man to his execution. It was brought to public attention by the 1995 film Dead Man Walking, based on a book (1993) of the same name by Sister Helen Prejean, which tells of her correspondence with and visits to a murderer on Death Row.

The phrase dead man walking occurs often in many different contexts, yet somehow it has avoided decline into a moribund cliché. Thomas Hardy used it as the title of a vivid poem about what a psychiatrist might classify as "major depressive disorder, recurrent - severe":

They hail me as one living,

    But don't they know

That I have died of late years,

    Untombed although?

 

I am but a shape that stands here,

    A pulseless mould,

A pale past picture, screening

    Ashes gone cold.

 

Not at a minute's warning,

    Not in a loud hour,

For me ceased Time's enchantments

    In hall and bower.

 

There was no tragic transit,

    No catch of breath,

When silent seasons inched me

    On to this death ....

 

—A Troubadour-youth I rambled

    With Life for lyre,

The beats of being raging

    In me like fire.

 

But when I practised eyeing

    The goal of men,

It iced me, and I perished

    A little then.

 

When passed my friend, my kinsfolk

    Through the Last Door,

And left me standing bleakly,

    I died yet more;

 

And when my Love's heart kindled

    In hate of me,

Wherefore I knew not, died I

    One more degree.

 

And if when I died fully

    I cannot say,

And changed into the corpse-thing

    I am to-day,

 

Yet is it that, though whiling

    The time somehow

In walking, talking, smiling,

    I live not now.

The idea of a dead man walking also occurs in a fragment of the fourth century B.C. comic playwright Timocles:

Money is blood and soul for mortals. Whoever does not have it and has not acquired it, that one walks as a dead man among living men.

τἀργυριόν ἐστιν αἷμα καὶ ψυχὴ βροτοῖς.
ὅστις δὲ μὴ ἔχει τοῦτο μηδ᾽ ἐκτήσατο,
οὗτος μετὰ ζώντων τεθνηκὼς περιπατεῖ.