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Tuesday, November 26th 2019
Tue, Nov 26th 2019

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21Chris_Leong15dHegel - A Very Short Introduction by Peter Singer - Book Review Part 1: Freedom Hegel is a philosopher who is notorious for being incomprehensible. In fact, for one of his books he signed a contract that assigned a massive financial penalty for missing the publishing deadline, so the book ended up being a little rushed. While there was a time when he was dominant in German philosophy, he now seems to be held in relatively poor regard and his main importance is seen to be historical. So he's not a philosopher that I was really planning to spend much time on. Given this, I was quite pleased to discover this book promising to give me A Very Short Introduction, especially since it is written by Peter Singer, a philosopher who write and thinks rather clearly. After reading this book, I still believe that most of what Hegel wrote was pretentious nonsense, but the one idea that struck me as the most interesting was his conception of freedom. A rough definition of freedom might be ensuring that people are able to pursue whatever it is that they prefer. Hegel is not a fan abstract definitions of freedom which treat all preferences the same and don't enquire where they come from. In his perspective, most of our preferences are purely a result of the context in which we exist and so such an abstract definition of freedom is merely the freedom to be subject to social and historical forces. Since we did not choose our desires, he argues that we are not free when we act from our desires. Hegel argues that, "every condition of comfort reveals in turn its discomfort, and these discoveries go on for ever". One such example would be the marketing campaigns to convince us that sweating was embarrassing (…/how-advertisers-convinced…/ [
12ofer16d--Daniel Kahneman, Thinking, Fast and Slow To the extent that the above phenomenon tends to occur, here's a fun story that attempts to explain it: At every moment our brain can choose something to think about (like "that exchange I had with Alice last week"). How does the chosen thought get selected from the thousands of potential thoughts? Let's imagine that the brain assigns an "importance score" to each potential thought, and thoughts with a larger score are more likely to be selected. Since there are thousands of thoughts to choose from, the optimizer's curse [] makes our brain overestimate the importance of the thought that it ends up selecting.
8Chris_Leong15dBook Review: Waking Up by Sam Harris This book aims to convince everyone, even skeptics and athiests, that there is value in some spiritual practises, particularly those related to meditation. Sam Harris argues that mediation doesn't just help with concentration, but can also help us reach transcendental states that reveal the dissolution of the self. It mostly does a good job of what it sets out to do, but unfortunately I didn't gain very much benefit from this book because it focused almost exclusively on persuading you that there is value here, which I already accepted, rather than providing practical instructions. One area where I was less convinced was his claims about there not being a self. He writes that when meditating allows you to directly experience this, but worry he hasn't applied sufficient skepticism. If you experience flying through space in an altered mental, it doesn't mean that you are really flying through space. Similarly, how do we know that he is experiencing the lack of a self, rather than the illusion of there being no self? I was surprised to see that Sam was skeptical of a common materialist belief that I had expected him to endorse. Many materialists argue against the notion of philosophical-zombies by arguing that if it seems conscious we should assume it is conscious. However, Sam Harris argues that the phenomenon of anaesthesia awareness, waking up completely paralysed during surgery, shows that there isn't always a direct link between appearing conscious and actual consciousness. (Dreams seem to imply the same point, if less dramatically). Given the strength of this argument, I'm surprised that I haven't heard it before. Sam also argues that split-brain patients imply that consciousness is divisible. While split-brain patients actually still possess some level of connection between the two halves, I still consider this phenomenon to be persuasive evidence that this is the case. After all, it is possible for the two halves to have
6Kaj_Sotala16dRecent papers relevant to earlier posts in my multiagent sequence []: Understanding the Higher-Order Approach to Consciousness []. Richard Brown, Hakwan Lau, Joseph E.LeDoux. Trends in Cognitive Sciences, Volume 23, Issue 9, September 2019, Pages 754-768. Reviews higher-order theories (HOT) of consciousness and their relation to global workspace theories (GWT) of consciousness, suggesting that HOT and GWT are complementary. Consciousness and the Brain [] , of course, is a GWT theory; whereas HOT theories suggest that some higher-order representation is (also) necessary for us to be conscious of something. I read the HOT models as being closely connected to introspective awareness [] ; e.g. the authors suggest a connection between alexityhmia (unawareness of your emotions) and abnormalities in brain regions related to higher-order representation. While the HOT theories seem to suggest that you need higher-order representation of something to be conscious of a thing, I would say that you need higher-order representation of something in order to be conscious of having been conscious of something. (Whether being conscious of something without being conscious of being conscious of it can count as being conscious of it, is of course an interesting philosophical question.) Bridging Motor and Cognitive Control: It’s About Time! [] Harrison Ritz, Romy Frömer, Amitai Shenhav. Trends in Cognitive Sciences, in press. I have suggested [] that control of thought and control of behavior operate on similar principles; this paper argues the same. From Knowing to Remembe
4TurnTrout16dI was having a bit of trouble holding the point of quadratic residues [] in my mind. I could effortfully recite the definition, give an example, and walk through the broad-strokes steps of proving quadratic reciprocity. But it felt fake and stale and memorized. Alex Mennen suggested a great way of thinking about it. For some odd prime p, consider the multiplicative group (Z/pZ)×. This group is abelian and has even order p−1. Now, consider a primitive root / generator g. By definition, every element of the group can be expressed as ge. The quadratic residues are those expressible by e even (this is why, for prime numbers, half of the group is square mod p). This also lets us easily see that the residual subgroup is closed under multiplication by g2 (which generates it), that two non-residues multiply to make a residue, and that a residue and non-residue make a non-residue. The Legendre symbol then just tells us, for a=ge, whether e is even. Now, consider composite numbers n whose prime decomposition only contains 1 or 0 in the exponents. By the fundamental theorem of finite abelian groups and the chinese remainder theorem, we see that a number is square mod n iff it is square mod all of the prime factors. I'm still a little confused about how to think of squares mod pe.