Two drives run deep and conflicted in most of us. They go by different names, id and superego, yang and yin, assimilation and accommodation, the courage to change; the serenity to accept, “all about ...
This quote is solidly attributable to Twain. The Mark Twain House lists it amongst his famous quotations, and TwainQuotes traces it more specifically to a 1901 note to the Young People's Society of ...