Modern philosophy begins with Descartes, whose fundamental certainty is the existence of himself and his thoughts, from which the external world is to be inferred. This was only the first stage in a development, through Berkeley and Kant, to Fichte, for whom everything is only an emanation of the ego. This was insanity, and from this extreme, philosophy has been attempting, ever since, to escape into the world of every-day common sense.p. xxi.

Quote