It offers, he says, a theatrically stylised presentation, aiming at a seamless flow of events. Why Tess? Clements praises its narrative strength. He instances the love triangle, the themes of unrequited love, obsession and pride.
Both the philandering Alec and the pompous pseudo-liberal Angel are, claims Clements, aspects of Hardy himself, and the truth which therefore emerges is tied brilliantly with the landscapes, which offer the sexual undertones of budding and blooming, spring, the full summer of love, the low ebb of fortunes in the bitter wintry swede fields.
Clements has made Alec and Angel less black and white, more rounded than they are in Hardy, to avoid an over schematic effect. "Men like Alec are not intrinsically evil, despite our keeping in Hardy's devil references. Alec is driven by his obsession for Tess, but he does not know what love is. He's used, too, to getting his own way."
Angel is a more dangerous sort, a fence-sitter, a misguided romantic who has to grow up the hard way - but not, his latest re-creator thinks, malicious. "The crucial scene is the one of their confessions. He can't handle Tess's infidelity. He's built her up as this rose-cheeked virginal milkmaid and has this romantic vision of her while all the time she's saying he must know her as she is.
"What makes Tess different from other milkmaids, what Alec and Angel see in her, is her unusual intelligence. She can explain things in a simple, articulate way. She's educated, can read and write and in another age might have been a teacher. But society and the pattern of her life determine her way.
"She's attractive, incredibly bright, calmly enigmatic - and nigh on perfect, but not quite." A casting nightmare, but Clements believes Tara Woodward catches the character finely.
"She mustn't be saintly. Her pride gets in her way. At times you call out for her to take the easy way, but pride won't let her."
Her fineness, then, lies not in absence of wrong but in purity of motive. With Alec she is half raped, half seduced. "She is flattered by his attention and excited by what is dangerous." Victorian censors, Clements believes, led to the muffling of her sexual appetite, but he sees Hardy clearly signalling the relationship continued willingly after the initial seduction. "She's not repelled by the sexual act with Alec, but that, though she's attracted to him, she does not love him." Purity of motive again.
Adapted by Colin Mayes and Mark Clements. Runs 3 hours, 20 minutes. Salisbury Playhouse until April 13. Tickets: 01722 320333. Michael Fry's adaptation is revived by the Royal Exchange Theatre, Manchester, until May 4, then tours to Wigan, Burton-upon-Trent, Brighton, Gillingham, Kingsbridge, Chelmsford, Crewe, Egremont, Doncaster and Bedford. Details: 0l61 833 9833.