Ivan Illich, the philosopher whose voice can still be heard from time to time on Ideas on CBC Radio, bases his critique of western culture in the twelfth century (not a Dark Age at all, but the peak of the first Industrial Revolution), a time that he seems to have absorbed into his being, and of which he speaks and writes intimately; from that momentous time he is able to show us today advancing into a disembodied world. Part of his thesis is that the Church, in institutionalizing the Gospel (which itself promised to embody us in the flesh), created the conditions for the experience of mechanization that shaped human sensibility in the West during the ensuing “epoch of instrumentality” (culminating in the nineteenth century) and evolved into the virtualization of present-day culture that teaches us to inhabit immune systems rather than bodies—that is, as Illich demonstrates, we have come to inhabit the bodies that the Windows operating system requires of us. This is one of those books that demonstrate thinking in action, and like a great story or a great poem that inspires you to want to write one yourself, it makes you want to think, to do some thinking yourself. For Illich, like Gilbert Ryle, like Walter Benjamin, thinking, and thinking out loud, is a means of embracing reality, of mingling with the world. David Cayley, whose work is often heard on CBC Ideas, has done a great service in preparing The Rivers North of the Future: The Testament of Ivan Illich (House of Anansi), a text that makes a perfect companion to The Fabric of Reality by David Deutsch, The Spell of the Sensuous by David Abram, the works of Walter Benjamin and The Tibetan Book of the Dead.