"The greatest intellectual geniuses in both ancient and modern times led continent lives, and there is yet to be recorded one individual who freely expended seminal fluid who ever amounted to anything. In most cases, individuals who have achieved have been forced by necessity to abstain from sexual indulgence, as Cervantes, who wrote Don Quixote while in prison, or Dante who wrote his Divine Comedy while in exile. Milton wrote "Paradise Lost" when blind and when he did not indulge in sex. Sir Isaac Newton, active in intellect until the age of 80, led a continent life from birth, and so did Leonardo da Vinci and Michelangelo, both of whom retained their creative genius [until] an advanced age.
[...]
Hutchinson has recorded three cases of temporary blindness, all in men, the result of sexual excess after marriage (Archives of Surgery, Jan., 1893). The old medical authors attributed many evil results to excess in coitus. Thus Schurig brings together cases of insanity, syncope, epilepsy, loss of memory, blindness, baldness, unilateral perspiration and death attributed to this cause; of death many cases are given, some in women."
