(Replying to myself to avoid the "this comment was edited" mark.)
The link is to an unsourced quote, and Google just turns up repetitions of it. Given the striking relationship between the quote and the reputation of its purported utterer, I am inclined to doubt its authenticity; not because it sounds like something he wouldn't have said, or that he would have said, but because the idea that he said it is attractive enough to explain its repetition in quotes files everywhere.
I was writing a reply arguing about fully general counterarguments & motivated skepticism, then I realized that doesn't make you wrong plus my reply was clearly guilty on both those points, so I deleted it and instead I've had a closer Google & replied to the original with a more authentic source.
This thread has an experimental format for posting rationality quotes. Here is the format:
For those posting quotes:
Post the quote as usual, but not the author, original language translated from, or other information. That information is to be input after the quote according to the following format:
[Source](http://linkgoes.here "hovertext goes here")
For example:
>When an idea is wanting, a word can always be found to take its place.
[Source](http://www.quotationspage.com/quote/30216.html "Goethe, translated.")
The source information will be available by hovering the mouse over "Source", without opening a new page. This format allows quotations to be evaluated with less context available, with all that entails. I hope this allays some of the uncertainty regarding why words of the Bible or authors such as Nietzsche are sometimes poorly received. People are encouraged to vote without considering the source information. If locally idolized people said genuinely silly things even considering the context, feel free to post those as well, but please use your best judgement as to whether or not taking it out of context is fair to the speaker.
Please use your own judgement in deciding which quotes thread to post material. This isn't intended to compete with the main thread, it's an experiment to see if people like a different format better. Some people thought this format, or something like it, should simply be tried on the next regular quotes thread to minimize any disruption caused by having multiple threads, while others thought disruption wold be minimized by having a separate thread and leaving the main thread as normal. This is what I decided to do.
The usual rules apply, except that there is no fixed limit to the number of quotes one may submit, because I'd like to populate this thread without taking too much from the usual thread.