Time for another philosophy-filled episode! This time, Pat is joined by Dr. Lydia McGrew to help us think through external world skepticism. Is there really a world beyond our minds, or might everything we experience be the result of some malignant spirit manipulating our thoughts, as Descartes once suggested? Most people refuse to take these absurd hypotheticals seriously, but philosophers have often struggled to articulate just why these situations are, in fact, irrational. Fortunately, Dr. McGrew has some really good published material on the problem of external world skepticism, which we discuss in this episode. You can learn more about Lydia McGrew at her website http://www.lydiamcgrew.com/  And subscriber to her YouTube channel at https://www.youtube.com/channel/UCSwhBk0vUSg_6prKkR82IDQ