The most popular musical group of all time, the Beatles also brought serious thought to the bubble gum-scented world of pop and rock music, with adventurous, profound, and sometimes mysterious lyrics that veered from the deliberate absurdity of “I Am the Walrus” to the rosy Rousseau-like fantasy of “When I’m 64” to the darkly existential/nihilist visions of “Eleanor Rigby” and “A Day in the Life.” In this lively new book, 20 Beatles-loving philosophers offer fresh insight into the lives and words of the Fab Four. Among the topics investigated are the groups’ critique of consumer culture; John Lennon and the Cold War; Paul McCartney’s philosophy of love, community, and politics; the Beatles’ struggle against the inauthentic; the ethics of chemically changed states of consciousness; the metaphysical standing of popularized Eastern meditation; and skepticism in the Beatles’ worldview.