GEB slowly builds up an analogy that likens inanimate molecules to meaningless symbols, and further likens selves (or "I"'s or "souls" if you prefer -- whatever

GEB slowly builds up an analogy that likens inanimate molecules to meaningless symbols, and further likens selves (or "I"'s or "souls" if you prefer -- whatever it is that distinguishes animate from inanimate matter) to certain special swirly, twisty, vortex-like, and meaningful patterns that arise only in particular types of systems of meaningless symbols. It is these strange, twisty patterns that the book spends so much time on, because they are little known, little appreciated, counterintuitive, and quite filled with mystery. And for reasons that should not be too difficult to fathom, I call such strange, loopy patterns "strange loops" throughout the book, although in later chapters, I also use the phrase "tangled hierarchies" to describe basically the same idea. -- Douglas R. Hofstadter