Why Impractical Knowledge is More Efficient<\/h2>\n
Imagine knowledge is like a tree:<\/p>\n
![\"\"](\"https:\/\/www.scotthyoung.com\/blog\/wp-content\/uploads\/2026\/09\/Tree-practical-advice.jpg\")
<\/figure>\n<\/div>\nAt the base of the tree are principles. These are the things that are least contingent on specific states of the world, and are most generally true. This category includes stuff like F = ma<\/em> or the conservation of momentum or energy.<\/p>\n These principles are general, but, by themselves, they\u2019re often insufficient for a lot of situations you care about. You need to know a lot more than just F = ma<\/em> to design a good bridge or rocket ship. As we travel up the trunk, we get to branching points. These represent splits in the state of the world.<\/p>\n For example, it is true that heavier objects and lighter objects fall at the same speed. Yet there are domains where air resistance is practically irrelevant (e.g., lead ball vs. solid gold ball), and domains where this becomes a noticeable factor (e.g., feathers vs. rocks).<\/p>\n As you learn more about a specific, concrete situation you\u2019re in, you branch more and more until you finally come to the leaves of the tree. The leaves of the tree are practical advice. They\u2019re the kinds of \u201ctips\u201d you might give someone who doesn\u2019t know much about a particular domain, deep down, and just wants to know what sorts of action they should take. This would be things like \u201cmake your propeller blades exactly this shape to minimize air resistance.\u201d<\/p>\n There are far more leaves than there are trunks. And each leaf only covers an incredibly narrow subset of possible states of the world, so, to reasonably \u201ccover\u201d much of the space of possibilities, you need to learn tons and tons of different advice \u201cleaves\u201d for tons and tons of different cases.<\/p>\n Thus, if you want to maximize the breadth of your useful knowledge, meaning the number of concrete situations it applies to, you\u2019re better off learning lower down the tree of knowledge, focusing on ideas and knowledge that are less dependent on specifics.<\/p>\n Let\u2019s try this analogy with a few examples. <\/p>\n Consider a goal of getting in shape.<\/strong><\/p>\n Here, the leaves would be a particular workout plan you decide to follow. Further down the branches, would be principles like progressive overload and recovery. Towards the trunk are more basic ideas like energy metabolism, muscle and cardiac physiology, and so on.<\/p>\n Following a specific workout plan is fine\u2014as long as your situation is close enough to the situation that plan was developed for. But what if the workout plan was made for a serious athlete in their twenties, and you\u2019re 55 and recovering from an injury? Then, the specific plan is unlikely to work for you, and it may even be counterproductive.<\/p>\n In contrast, the knowledge of more basic principles would still apply and could steer you to more applicable advice on a different branch of the tree of knowledge.<\/p>\n Or consider starting a business.<\/strong><\/p>\n The leaves here are particular tactics like \u201cbuy ads on Facebook\u201d or \u201ccold call purchasing managers at mid-sized firms.\u201d Again, if you\u2019re in a domain where this advice applies, perhaps you\u2019re receiving it from someone in a very similar business, this may be what you need to hear.<\/p>\n But if you\u2019re not, these tactics may be counterproductive. Instead, you should focus on ideas closer to the trunk. A little further down the tree are basic ideas of entrepreneurship like \u201cproduct-market fit\u201d, \u201cminimum viable product\u201d and \u201cmarket research.\u201d And towards the base are fundamental concepts like \u201csupply and demand.\u201d<\/p>\n Or consider the topic I write most about: effective learning.<\/strong><\/p>\n If you\u2019re studying for an exam, advice for how to pass your particular exam would be the leaves. Further down the branches are somewhat more general ideas for tackling multiple-choice questions or organizing your studying materials. Finally, at the trunk, you get to bedrock ideas about learning like the spacing effect or retrieval practice.<\/p>\n The latter principles are most universal, even if they leave ambiguity for how you should deal with any particular situation.<\/p>\n There are a few common objections to focusing on principles over practicalities:<\/p>\n First, there\u2019s the objection that principles aren\u2019t enough to constrain decision-making.<\/strong> This is true. Rarely does learning a deep principle give you all you need to decide the best course of action in a real-life situation. Usually there are too many other considerations at play.<\/p>\n But, learning principles is still more efficient. It\u2019s just that principles need to be supplemented with more specific knowledge to get you to the correct answer.<\/p>\n To continue our arboreal analogy, imagine you\u2019re trying to find a small bird in a tree. If I tell you \u201che\u2019s on the third branch from the right\u201d, it doesn\u2019t tell you exactly where he\u2019s located, but it does give you a good place to look. In contrast, only knowing whether or not he is on a particular leaf is only helpful if he is on that leaf\u2014in most cases, that information doesn\u2019t inform your search very effectively. Specific advice is only helpful if it applies to the situation you\u2019re in.<\/p>\n Second, there\u2019s the objection that the principles don\u2019t actually describe the world.<\/strong> Essentially, a theoretician has come up with an elegant-sounding principle that doesn\u2019t translate directly into useful advice.<\/p>\n This is an issue, but it\u2019s more typically the case that the principles are still largely undiscovered or don\u2019t constrain the problem enough. Going back to our tree analogy, this is like being able to see a bunch of leaves while we don\u2019t know where of all the branches underneath the canopy are. We can guess at some, but those guesses may be wrong.<\/p>\n Our knowledge is correct, as far as it goes, but it may not go as far as we need it to. In domains where principles strongly determine practical advice, such as physics and engineering, there\u2019s a strong rationale for learning the fundamental principles. In domains where principles only weakly determine the practical advice, such as entrepreneurship or second-language learning, principles are still worth learning, but they\u2019ll have to be supplemented with a lot of situation-specific advice.<\/p>\n None of this negates the idea that learning principles is more efficient. It\u2019s simply that sometimes we don\u2019t know what the principles are, and so only practical advice can be generated.<\/p>\n Finally, there\u2019s the possibility that figuring things out from fundamental principles is intractable, so we again have to go by practical advice.<\/strong><\/p>\n Continuing our analogy, the closer to the trunk you go, the more mental work needs to be done to figure out where the branch points are and where the leaves end up.<\/p>\n This is also a fair critique, and it\u2019s one reason we have hierarchical domains in the first place. But this simply means that, for really complicated domains, we occasionally need more knowledge from higher up the tree to make the principles useful. Even so, because the span of principles is so broad, they still tend to be more efficient for learning.<\/p>\n Applying this idea reflexively, the idea that \u201clearning principles is more efficient than practical advice\u201d is itself a deeper principle. So, what are the practical consequences?<\/p>\n Consider the mass of practical advice books on topics like productivity, diet or personal finance. How many of these are just leaves? The new \u201cfat-busting\u201d diet plan that claims it will have you losing fifteen pounds in fifteen days? The specific habits your favorite author uses to write books? The budget plan for retiring by 45?<\/p>\n If you were only going to read one book, perhaps one practical book would be best. After all, fundamental principles don\u2019t sufficiently constrain advice, so they won\u2019t give you something concrete to do. Whereas maybe you happen to be in the exact situation the author describes and thus can benefit from their advice?<\/p>\n But if you\u2019re going to read more than one book, don\u2019t start with the leaves of practical advice. If the trunk of the knowledge tree is largely within an academic field, such as nutrition or psychology, read a textbook. If the trunk of the tree is within the scope of some professional practice, read a book that aims to give the basic information in an unbiased way; For Dummies books and other general readers are good examples.<\/p>\n Even more generally, make it a personal maxim to try to read as much as possible of the \u201ctrunks\u201d of various domains. Then, when you do have a practical problem that requires detailed knowledge of the leaves, you may still have some work to do, but you will have already completed some of the most important learning.<\/p>\n \n","protected":false},"excerpt":{"rendered":" Most readers prefer useful advice to abstract theory. They shouldn’t.<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[3],"tags":[],"class_list":["post-18674","post","type-post","status-publish","format-standard","category-personal-development","entry"],"acf":[],"yoast_head":"\nSome Examples<\/h2>\n
Dealing with Some Objections<\/h2>\n
Applications for Real Life<\/h2>\n