In all aspects of human endeavour, it is tempting to wonder how the achievers of yesteryear might stack up against their modern counterparts. How would Jesse Owens, the legendary sprinter of the 1930s, fare against Usain Bolt?
The question needs to be hedged with conditions: what if Owens had enjoyed all Bolt's advantages training and diet science, not to mention high-tech spikes and a synthetic, rather than a cinder, track?
It quickly becomes a meaningless comparison. Owens will always be what he was because he did what he did when he did.
And the same caveat applies to the bid by three descendants of the original adventurers to "complete" Ernest Shackleton's journey to the South Pole.
Henry Worsley, Will Gow and Henry Adams all of whom have family connections to members of Shackleton's 1908 Nimrod expedition last week set off on a 1400km trek to the Pole. Shackleton himself, defeated by severe weather and a food shortage, turned back just 156km short of his target and later commented that it was better to be "a live donkey than a dead lion".
If the modern group succeeds, it will bring a satisfying symbolic closure to a magnificent episode in the life of one of history's truly great explorers. But they will be the first to acknowledge that their achievement is not a recreation of Shackleton's.
These men will pull space-age sledges, with solar panels to charge communications equipment and batteries for iPods, which will offer them comfort and energy. Shackleton and his men had sledges of ash and oak, and only wool and true grit between them and the elements.
Like most if not all modern adventurers, this summer's polar trekkers cannot hope to emulate their predecessors. Let their success be a tribute to much harder men who went before them.