I found myself reading it when I was researching my new book Scandal, about the strange story of why homosexuality was criminalised in 1885, and Harris knew many of the people involved. It is bizarre and hard to put down (and not really because of the pornography, I assure you).
The trouble is that Harris is widely believed to have been a liar, and his first biographer chose the sub-title 'The biography of a scoundrel'. It doesn't help that he had extraordinary powers of recall, which means - for example - that most of the copious poetry he quotes in his autobiography are clearly taken from memory and therefore not completely accurate.
This is a pity because Harris really did know everybody in the 1880s and 1890s in London and beyond and what he remembers is worth remembering. The pornography meant that unexpurgated editions were banned until 1962.
By the fourth volume you begin to feel his concentration is flagging, only to have what is an absolutely gripping account of his investigation into the abortive Jameson Raid in 1895, which led to the Boer War and arguably the rift with Germany.
But I have learned something from Harris and it followed from his own conviction that he was too short to be a great athlete. He decided he had to develop in himself the physical and mental control he needed to succeed. These are detailed at great length. Extraordinary self-confidence clearly helped.
But it made me realise how little our own generation spends on developing their minds, compared to the vast time and money they spend developing their bodies. Harris tried both, but the time he spent learning European languages and mastering French and German literature, and deepening his Shakespeare scholarship, puts my own generation to shame.
Or perhaps it just puts me to shame...
By coincidence yesterday, there was an item on BBC Radio 4 about education and the mismatch between the effort put into physical education compared to what you might call mental education, or at least mental health.
This is the emerging debate in education policy these days, and it is hampered because it isn't clear what works - certainly David Cameron's Blairite backing for parenting classes are not the holy grail we are looking for. The question is, if people don't want to develop their own potential, whether anything really ought to be done about it.
The answer seems to be yes, but punishing them with parenting classes seems paradoxcially like treating them too like children.
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