Summary: Analytic Idealism in a Nutshell by Bernardo Kastrup - Chester Grant

1. This is a book about the nature of reality. It elaborates on the best hypothesis we have today, based on leading-edge science and analytic reasoning, about what reality is.<br>2. The scientific method can only definitively answer questions of behavior: what nature does, as opposed to what it is.<br>3. After all, science is based on controlled empirical experimentation: it poses a question to nature in the form of an experiment, which nature then answers by doing something in response.<br>4. This doing is a behavior of nature, not an unambiguous expression of what nature is, as different hypotheses about the essence of reality may be equally consistent with the observed behavior. Moreover, the litmus test of scientific theories is their ability to predict what nature will do next, which again is a question of behavior.<br>5. Indeed, in addition to science, this book also leverages the methods of philosophy, particularly metaphysics, the area of philosophy dedicated to questions of being.<br>6. More specifically, beyond the empirical adequacy of the hypothes is it puts forward, this book also leverages softer truth guidelines such as conceptual parsimony, internal logical consistency, overall coherence, and explanatory power. These guidelines cannot lead us to definitive answers to questions of being, but surely allow us to rank the hypotheses at hand and figure out the most likely one. This is the spirit of this book.<br>7. This way, Analytic Idealism embraces realism (i.e., there is an external world out there, independent of our individual minds; independent of our observation, volition, fantasies, preferences, rituals, etc.), naturalism (i.e., the phenomena of the external world unfold spontaneously, according to nature’s own inherent dispositions, and not according to external intervention by a divinity outside nature), rationalism (human reason can recognize and model the regularities of nature’s behavior), and reductionism (complex phenomena can be explained in terms of simpler ones).<br>8. However, Analytic Idealism then infers that the external world is of the same ontic kind or essence as our individual minds. In other words, it posits that the world out there is mental<br>9. For now, though, notice that technology necessitates no ultimately correct understanding of the nature of reality; it only needs empirically convenient fictions.<br>10.To see how, consider that a 5-year-old kid can be world champion playing a computer game without having the slightest idea of what the game actually is—that is, of the computer hardware and software that constitute the game. To  be world champion, all the kid needs is a convenient fiction in terms of which to relate to the game.<br>11. And it may go like this: there is a little man inside the screen; I am that little man; if I shoot those other little men in the screen, I score points; if I get shot or touch this or that wall, I die; and so on. Each and every element of this fiction is utterly false: there is no little man inside the screen; you are not inside the screen; you are not shooting, or getting shot by, anyone; there are no walls to touch; and you don’t die from playing the game.<br>12. Yet, the fiction is convenient in that the game behaves, for all applicable purposes, as if the fiction were true; and that’s all the kid needs to play it well and be crowned world champion.<br>13. We believe that our perception is a kind of transparent window into the world, revealing to us the world as it is in itself.<br>14. Take an airplane, for instance: it has a number of sensors—such as air speed, pressure, and orientation sensors—which measure the states of the sky outside the airplane. The resulting measurements are then displayed to the pilot in an encoded manner, in the form of dial indications in the airplane’s dashboard. As such, the airplane’s dashboard conveys accurate and important information about the sky outside, albeit in an encoded form. The pilot must take this encoded information seriously, lest the airplane crashes.<br>15. Just like the airplane, we, too, are equipped with sensors to collect information about the world surrounding us: our retinas, eardrums, taste buds, mucous lining of the nose, and outer surface of the skin make measurements of the states of the environment surrounding us. The results of these measurements are then represented on the screen of perception: what we see, hear, touch, taste, and smell. As such, the screen of perception is entirely analogous to the airplane’s dashboard: both display information about our environment that was collected by our sensors.<br>16. Yet, as we’ve just seen, the airplane’s dashboard does not need to look like the sky to convey accurate, relevant, and actionable information about the sky.<br>17. Instead, perception is like a dashboard of dials: it contains information about the world only in an encoded form, thereby limiting the entropy of our internal states,...