If someone such as myself wanted to understand the philosophy of functional languages, do you have any book you'd recommend? Learning the languages is easy enough, but if I ever tried them I'd want to do it using the ideals of functional programming vs. trying to contort the language to be something it isnt't.
I'm noticing a trend more and more where developers move to FP over OOP after a decade or so in their career. I feel if I don't give it a look, I could be missing an obvious lesson.