You can't get a more clear example of the fact that no matter how brilliant, creative, deep or original are the thoughts of great philosophers, they are still entirely of their own time, than Immanual Kant's attitude towards masturbation. Pigliucci mentioned in passing, during the Sunday Philosophy-in-Manhattan meet up that Kant was anti-masturbation.
And sure enough, according to Wikipedia's History of Masturbation (yes it's a thing):
Immanuel Kant regarded masturbation as a violation of the moral law. In the Metaphysics of Morals (1797) he made the a posteriori argument that 'such an unnatural use of one's sexual attributes' strikes 'everyone upon his thinking of it' as 'a violation of one's duty to himself', and suggested that it was regarded as immoral even to give it its proper name (unlike the case of the similarly undutiful act of suicide). He went on, however, to acknowledge that 'it is not so easy to produce a rational demonstration of the inadmissibility of that unnatural use', but ultimately concluded that its immorality lay in the fact that 'a man gives up his personality … when he uses himself merely as a means for the gratification of an animal drive'.Kant, as it says in the Wiki for him, "... is considered the central figure of modern philosophy."
It's pretty amazing that such an important figure in philosophy would have such an absurd view of masturbation. But that view as all the rage in Europe at the time, thanks no doubt to Christianity. And Kant was big into Christianity.
The ancient Greeks, who invented philosophy, were much more relaxed about masturbation:
The ancient Greeks regarded masturbation as a normal and healthy substitute for other forms of sexual pleasure. They considered it a safety valve against destructive sexual frustration. The Greeks also dealt with female masturbation in both their art and writings. One common term used for it was anaphlan, which roughly translates as "up-fire"I had never heard of this anaphlan before but others certainly have as can be seen in this Google search. Although Club Anaphlan of Tampa Florida no longer exists, judging by the fact that it no longer has a web site. Although it seems that it was a swingers club, which is odd since anaphlan means masturbation and that doesn't seem worth going to a club for.
In any case most of us are already members of Club Anaphlan. Presumably Kant was not, although let's face it, he probably really was and was just ashamed of it.