Samuel Pepys could bring himself to orgasm with the 'strength of his fancy alone', and did, on the ferry home from the Admiralty, in the street...you get the idea.  He is particularly proud of the achievement and notes it with no small satisfaction in his inestimable diary.  The only time he feels a little bit bad about his solitary climax is in the not so solitary venue of St Olave's Church, at Midnight Mass 1667, when he is so turned on by the prospect of the Queen and her ladies, he masturbates to completion whilst sitting next to his wife.

By 1720, there had been a huge shift in the way masturbation was regarded: it was no longer a part of the human experience to be noted along with diet, work or pretty pictures, it had become something furtive and filthy, to be resisted.  In the late 17thC, possibly as a backlash against Charles IInd's permissive reign, moralists began to get busy on the subject of sexuality.  Sodomy and masturbation were the two favourite topics, and an extraordinary amount of time and energy was given to the prevention of both.  

John Marten was a quack doctor, prosecuted for having obscene material printed in 1708 (a pseudo-medical manual).  Undeterred, in 1712, he produced the 88 page treatise Onania, or the Heinous Sin of Self-Pollution and All Its Frightful Consequences, in Both Sexes, Considered.  And boy, did John Marten consider it; writing in detail about how an individual might harm themselves through masturbation, and advocated his 'Strengthening Tincture' and Prolific Powder' to prevent the urges and repair the damage.  Onania is a vehicle to sell quack medicine, yet for some reason it became hugely popular, going through reprint after reprint: clearly hitting a 'nerve' at the time.  By 1724 it was being printed in Boston and masturbation became the secret scourge of God-fearing Americans.  

Viewed practically without the benefit of modern science, there is a certain logic to Marten's stealthy, opportunistic theories: sweet, pretty children hit puberty and become secretive, spotty and sometimes sick (cystic fibrosis sufferers who worsen during puberty anyway seem to have illustrated the decline of the chronic masturbator perfectly - not enough to be suffering a serious respiratory disease, you had to bear the burden of shame too).  The onset of sexuality and its attendant temptations towards masturbation is an obvious culprit, if not quite the right one and where he found blindness is a mystery.  

By 1760 Samuel Auguste David Tissot, eminent French surgeon, had written L'Onanisme; a more learned tract than Marten's but along much the same lines and just as much of a sensation.  The Enlightenment became rather less enlightened overnight.  After that, it was a free for all, with endless Victorian documents bearing such gems as bitten nails on a girl's right hand indicate that she is a secret despoiler of her own parts: her bitten nails are kept short for 'use', and because of the blisters 'acrid' female sexual fluids cause to the skin.  By 1890, there was almost no ailment masturbation could not cause, if applied frequently enough, and with sufficient vigour.  

In America things were arguably worse.  Two of the most popular American foodstuffs: Kellog's Corn Flakes and Graham Crackers are both inventions by men obsessed with the prevention of masturbation.  Their 'clean' starch-based foods were intended to direct energy away from the sexual parts.  It would be kind to say that both men had 'issues', but their creations remain popular, although their efficacy as anti-masturbation aids is in doubt.  

It wasn't until after WWII, when the famous Kinsey Reports exposed so much about human sexuality that masturbation ceased to be viewed as potentially health-threatening.  The famous statistic: 98% of the population masturbate and 2% are liars brought a secretive act into the public eye, but it took until the 1960s for the pall of shame to lift from solitary sex.  Some would argue the stigma remains, and in truth, there is a special and universally acknowledged quality to the derision encapsulated in the phrase, 'What a wanker.'