On Critical Thinking

In 1847, a Viennese doctor named Ignaz Semmelweis proved that doctors were killing their patients by not washing their hands. The evidence was overwhelming. His colleagues rejected it and he died in an asylum. The problem was not the data. The problem was that accepting the data required his colleagues to conclude that they had been killing people for years. The mind does not process evidence neutrally. It processes evidence in the context of what accepting it would cost. Critical thinking is the most overused and most underspecified term in modern intellectual culture. Every educational institution claims to teach it. Every professional development programme includes it. Every political faction accuses its opponents of lacking it. And the actual practice of it, the sustained disciplined effort to think accurately about difficult questions in the face of the specific cognitive and social pressures that accurate thinking must overcome, remains as rare as it has ever been despite or perhaps because of all the attention directed at it. The reason is that most treatments of critical thinking address the wrong level of the problem. They teach logical fallacies, which is useful but insufficient. They teach statistical literacy, which is necessary but not sufficient. They teach Socratic questioning, which is valuable but limited. What they almost never address is the deeper problem: that the human mind did not evolve for accurate reasoning and that the cognitive and social forces working against accurate thinking are not external obstacles to be overcome by technique but are built into the architecture of the thinking apparatus itself. The books I referred for writing this piece collectively address this deeper problem. What follows is what they collectively teach about what genuine critical thinking actually is, why it is so difficult and what developing it actually requires. The Foundational Problem: Your Brain Is Not a Truth-Seeking Machine Begin with the most important and most consistently underappreciated fact about human cognition: the brain did not evolve to think accurately. It evolved to survive, reproduce and maintain social standing in small tribal groups and these evolutionary objectives are frequently in direct conflict with the objective of accurate reasoning about complex questions. Mercier and Sperber’s Enigma of Reason makes this argument with the most rigorous evolutionary and cognitive scientific foundation available. Their interactionist theory of reason holds that reasoning evolved not as a tool for individual truth-seeking but as a tool for social argumentation: for producing justifications for positions already held, for evaluating the arguments of others and for the management of reputation within groups whose cooperation was necessary for survival. The reasoning faculty is extraordinarily powerful at these social functions and systematically weak at the individual truth-seeking function that most critical thinking training assumes it is designed for. The practical implication is that when you use your reasoning faculty to evaluate a question you genuinely care about, in which you have a stake in the outcome, about which you have an existing position, the faculty is doing what it evolved to do: producing compelling justifications for the position rather than genuinely evaluating the evidence for and against it. The arguments produced feel like reasoning from evidence to conclusion. They are almost always rationalisation from conclusion to supporting evidence, with the disconfirming evidence systematically filtered by the very cognitive system that is supposedly doing the evaluation. Haidt’s Righteous Mind confirms this from the social psychology direction with evidence that is specifically devastating for sophisticated thinkers who believe their political and moral reasoning is more evidence-based than that of their opponents. His research demonstrates that moral and political reasoning in virtually all subjects, regardless of their measured intelligence or their explicit commitment to evidence-based thinking, follows the same pattern: rapid automatic moral intuitions produced by System 1 processing followed by the post-hoc construction of rational justifications by System 2. The sophisticated thinker’s advantage is not that they reason from evidence more reliably. It is that they produce more sophisticated and more convincing post-hoc justifications that are harder for others and for themselves to see through. Robson’s Intelligence Trap makes the corollary explicit. High intelligence is not a reliable protection against motivated reasoning, cognitive bias or the adoption of empirically unsupported beliefs. It is frequently a liability because it provides the cognitive tools to construct more elaborate rationalisations, to identify more sophisticated-seeming arguments for positions adopted on other grounds and to dismiss challenges to those positions with more convincing-sounding counter-arguments. The intelligent person who is wrong about something important is harder to reach with corrective information than the less intelligent person who is wrong about the same thing, precisely because their intelligence is in service of their defensiveness. Galef’s Scout Mindset is the most practically useful response to this foundational problem. Her distinction between the soldier mindset and the scout mindset is the most important single conceptual tool in this body of work for the person who wants to actually change their thinking rather than just understand why accurate thinking is difficult. The soldier’s job is to defend a position. The soldier’s cognitive system is therefore oriented toward finding evidence that supports their position and dismissing evidence that challenges it. The scout’s job is to find out what is actually there. The scout’s cognitive system is therefore oriented toward updating their map when new information conflicts with the existing one because an inaccurate map is more dangerous than a disappointing one. The soldier experiences the threat to their beliefs as a threat to themselves. The scout experiences the threat to their beliefs as useful information about where the map needs revision. The critical insight is that the switch between these orientations is not primarily cognitive. It is motivational and emotional. The scout mindset requires genuinely wanting to know what is true more than you want to be right. It requires having decoupled your identity from your beliefs sufficiently that being wrong about something does not feel like being diminished as a person. And it requires the specific emotional experience of updating a belief as a satisfying discovery rather than a humiliating defeat. These are not cognitive techniques. They are orientations that must be cultivated through the same kind of sustained practice that any other character development requires. The Sophisticated Failure Modes: Where Intelligent Thinking Goes Wrong The cognitive biases that Kahneman, Ariely and Dobelli catalogue are the failure modes of ordinary thinking. The critical thinking literature you need at your level addresses something more specific and more consequential: the failure modes of sophisticated thinking. The ways in which intelligence, expertise and the specific cognitive habits that make someone good at analytical reasoning in some domains make them systematically worse at accurate reasoning in others. The first sophisticated failure mode is what Tetlock calls the hedgehog problem. Isaiah Berlin’s famous distinction between the hedgehog, who knows one big thing and applies it everywhere, and the fox, who knows many things and applies different tools to different problems, maps precisely onto the accuracy of expert prediction. Tetlock’s research across twenty years of tracking expert predictions in political and economic domains found that experts who were most famous, most confident and most frequently cited in media were systematically less accurate in their predictions than less prominent experts with more diverse and more uncertain frameworks. The big idea that explains everything explains nothing accurately because no single framework captures the full complexity of the domains where accurate prediction matters most. The application to your own thinking is direct. The person who has built the formidable intellectual architecture that your reading across this conversation represents has also built the specific risk of becoming the hedgehog: the tendency to see every new problem through the frameworks that have been most rewarding to develop and to miss the specific features of new problems that those frameworks cannot accommodate. The metacognitive practice that guards against this is the regular deliberate effort to approach significant questions with frameworks that are foreign to your usual mode of analysis and to take seriously the answers those frameworks generate even when they conflict with your existing frameworks’ outputs. The second sophisticated failure mode is what Schulz documents as the structure of wrongness. The most consequential errors in sophisticated thinking are not the ones where you have obviously inadequate evidence. They are the ones where you have substantial evidence, sophisticated frameworks for interpreting it and high confidence in your conclusions, and where the evidence and frameworks are nevertheless leading you systematically in the wrong direction because of a prior assumption that you have not examined because it has never been challenged. Kuhn’s paradigm analysis is the structural account of this failure mode at the level of entire scientific communities. Schulz’s Being Wrong is the personal psychological account of the same failure mode at the level of the individual thinker. The conclusion that feels most certain, that has the most supporting evidence and that has been held the longest, is the conclusion that is most in need of the specific kind of interrogation that asks not what supports this belief but what would have to be true for this belief to be wrong and is any of that true. The third sophisticated failure mode is what McRaney documents in How Minds Change: the backfire effect and its variants. When people who hold a belief with significant emotional investment encounter strong evidence against it, they frequently strengthen rather than weaken their commitment to the belief. The evidence is processed not as information that should update the belief but as an attack that must be defended against and the defence produces a stronger articulation of the original position. The sophisticated thinker is not immune to this. They are better equipped to execute the defence because they have more sophisticated argumentative resources available for the counter-attack. Understanding the backfire effect is important both for managing your own thinking and for understanding why the straightforward deployment of evidence and argument so consistently fails to produce the belief change that your analysis shows should follow from it. The specific conversational and rhetorical approaches that do produce genuine belief change, which McRaney documents with unusual specificity, operate not through better arguments but through the creation of the psychological safety that allows beliefs to be examined without triggering the identity defence that produces the backfire. The Epistemic Standards Layer: How Do You Know What You Know Most sophisticated thinkers have never rigorously examined the epistemic standards by which they evaluate evidence, distinguish reliable from unreliable claims and decide when they have sufficient justification to hold a belief with a given level of confidence. These standards are typically implicit, inconsistently applied and calibrated to the norms of the specific domain in which the thinker was trained rather than to any principled account of what genuine justification requires. Tetlock and Gardner’s Superforecasting provides the most empirically grounded account available of what excellent epistemic standards actually look like in practice. The superforecasters who consistently outperform experts, intelligence analysts and prediction markets share a specific cluster of epistemic habits that constitute the most practically validated account of good reasoning under uncertainty available. They think in probabilities rather than in binary predictions. The question is never will this happen or not but how probable is each possible outcome given the available evidence. This shift from binary to probabilistic thinking is more consequential than it sounds because it forces the recognition of genuine uncertainty rather than the false confidence that binary framing produces, it provides a specific standard against which predictions can be evaluated over time and it makes the degree of confidence explicitly visible rather than hidden inside the assertion. They update continuously and proportionally in response to new information. Not the dramatic reversal of position that feels like genuine updating but the specific quantitative adjustment of probability estimates that new evidence warrants, neither under-updating in the direction of anchoring nor over-updating in the direction of overreaction to the most recent information. The discipline of proportional updating requires maintaining explicit probability estimates rather than vague impressions, which is uncomfortable but is the condition for genuine calibration over time. They actively seek disconfirming evidence. Not as a performance of open-mindedness but as a genuine epistemic practice of looking for the strongest available case against their current position before strengthening their commitment to it. The question what would most strongly challenge my current view is the most reliably productive question available for improving the accuracy of any analysis and it is the question that the soldier mindset most consistently fails to ask. They are calibrated about their own uncertainty. The superforecaster whose 70 percent confidence predictions are right 70 percent of the time is well calibrated. Most people, particularly experts in their own domains, are significantly overconfident: their 90 percent confidence predictions are right far less than 90 percent of the time. Developing genuine calibration, the accurate self-assessment of how confident you should be about specific claims, requires the sustained practice of making explicit probability estimates and tracking their accuracy over time. It is uncomfortable, revealing and the most direct available path to accurate self-knowledge about the quality of your reasoning. Goldacre’s Bad Science and Bergstrom and West’s Calling B******t provide the domain-specific epistemic standards for evaluating the scientific and statistical claims that are most consequential in your policy context and most systematically misrepresented in public discourse. The specific tools they provide, for evaluating study quality, for detecting statistical manipulation, for identifying misleading data visualisations and for recognising the specific forms of authority substitution that disguise poor evidence as rigorous science, are the practical implementation of the philosophical epistemic standards that Nagel and Okasha articulate at the level of principle. The specific Calling B******t framework is worth dwelling on because it addresses the specific form of sophisticated epistemic manipulation that is most consequential in your professional environment. B******t, in the technical sense that Bergstrom and West adopt from Harry Frankfurt, is communication that is produced without regard for its truth value. The bullshitter is not lying in the technical sense because lying requires a concern for the truth that is being strategically misrepresented. The bullshitter simply does not care whether what they are saying is true. They care whether it achieves the effect they intend. The specific modern forms of b******t that their framework addresses include: the misleading data visualisation that is technically accurate but constructed to create a false impression; the algorithm whose authority is invoked without the transparency that would allow its reliability to be evaluated; the big data claim that confuses the ability to find patterns in large datasets with the ability to distinguish meaningful from spurious patterns; and the scientific-sounding language that borrows the epistemic authority of science without the methodological rigour that justifies it. Each of these requires specific detection tools that general critical thinking training does not provide and that your policy role requires you to have. The Metacognitive Layer: Thinking About Your Thinking Genuine critical thinking at the highest level requires not just the application of thinking tools to external problems but the consistent application of those tools to your own thinking process. This metacognitive dimension is the one most consistently absent from critical thinking training and the one most consistently present in the practice of the best thinkers across every domain. Nagel’s epistemological framework provides the philosophical foundation for this metacognitive practice. The questions it forces about your own beliefs are the most productive available: what is the source of this belief and is that source reliable for this type of claim? What is the quality of evidence that justifies this belief and is it proportionate to the confidence I hold it with? What assumptions am I making that I have not explicitly examined and what would happen to the belief if those assumptions turned out to be wrong? These are not comfortable questions and the discomfort they produce is diagnostic: the belief about which these questions feel most threatening is usually the belief most in need of examination. Duke’s Thinking in Bets provides the most practically useful metacognitive framework for the specific challenge of evaluating your own decision-making over time. Her concept of resulting, the tendency to evaluate the quality of past decisions by their outcomes rather than by the quality of the process that produced them, is the most consequential single metacognitive error available. Good decisions sometimes produce bad outcomes through bad luck. Bad decisions sometimes produce good outcomes through good luck. The thinker who evaluates their decisions by their outcomes will incorrectly reinforce the thinking that produced lucky bad decisions and incorrectly abandon the thinking that produced unlucky good ones. The corrective is the deliberate habit of evaluating decisions by the quality of the process, the information gathered, the alternatives considered, the probability estimates made, the reasoning applied, independent of the outcome, which requires maintaining explicit records of decision processes rather than relying on the inevitably outcome-contaminated memory of how the decision was made. Jacobs’s How to Think makes the most important argument about the social and moral dimensions of critical thinking that the purely cognitive accounts miss. Good thinking, he argues, is not primarily a matter of having the right cognitive tools. It is a matter of being the right kind of person in relation to other people and to ideas. The person who genuinely wants to think well must be willing to be moved by evidence and argument, which requires the specific moral courage of changing your mind publicly when the evidence warrants it. They must be willing to engage charitably with positions they find repugnant, which requires the specific intellectual humility of recognising that even positions you are confident are wrong may contain something worth taking seriously. And they must be willing to belong to communities that include people whose thinking challenges rather than merely confirms their own, which requires the specific social courage of resisting the pull toward the epistemic comfort of the tribe. The critical thinking challenges you face in your policy role are not the challenges that introductory critical thinking courses address. They are the challenges of sophisticated thinking in genuinely complex domains under conditions of uncertainty, time pressure, political constraint and the specific motivated reasoning pressures that high-stakes institutional environments produce. The most consequential of these challenges and the specific thinking disciplines that address them are the following. The expertise trap. The domain expert’s deepest knowledge is simultaneously their deepest source of potential error because their expertise is embedded in the paradigm that defines their field’s current understanding. The policy expert who has spent twenty years developing expertise in a specific threat domain has also spent twenty years developing the specific blind spots of that domain’s current paradigm. The metacognitive practice that guards against this is the deliberate regular engagement with frameworks from adjacent domains, including the ones that feel most foreign to your established expertise, and the active search for the anomalies that your current framework cannot accommodate. The narrative capture problem. In policy contexts, the narrative that has achieved institutional consensus is typically treated as settled reality rather than as the current best approximation. The critical thinker in this environment must maintain the internal distinction between the narrative and the underlying reality that the narrative is supposed to represent, which requires the specific epistemic courage of questioning institutionally settled questions in contexts where questioning them is socially costly. The motivated reasoning of institutional loyalty. The person who has invested significantly in a policy position, who has staked institutional credibility on a specific analysis and who operates in an environment where changing your position is interpreted as weakness rather than intellectual honesty, faces the most powerful motivated reasoning pressure available. The specific practice that guards against this is what Galef calls the identity separation: the deliberate cultivation of an identity organised around the commitment to accuracy rather than around the specific positions that accuracy has previously led you to, so that updating those positions in response to new evidence feels like the expression of that identity rather than its betrayal. The complexity that defeats simplification. The most consequential policy questions are genuinely complex in the systems thinking sense: they have feedback loops, non-linear dynamics, emergent properties and second and third order effects that linear causal reasoning systematically misses. The critical thinking practice that addresses this is not more sophisticated linear reasoning but the genuine adoption of the systems thinking mode that Meadows provides as a complement to rather than a replacement of analytical reasoning. The b******t that wears the clothes of rigour. The Bergstrom and West framework is more directly applicable to your daily professional environment than most critical thinking tools because the specific forms of sophisticated b******t they catalogue, algorithmic authority, misleading data visualisation and statistical manipulation, are the forms most frequently encountered in the policy briefings, intelligence assessments and technical analyses that constitute your information environment. The specific tools for detecting them are a professional necessity rather than an intellectual luxury. The Unified Picture Pull everything in this body of work together and what emerges is a picture of genuine critical thinking that is both more demanding and more humanly grounded than the standard account. It begins with the honest acceptance that the mind you are thinking with is not a truth-seeking machine but an evolved social and argumentative organ whose natural operation produces the systematic biases, motivated reasoning and tribal epistemology that all the above books document. This acceptance is not a counsel of despair. It is the foundation of genuine epistemic humility and the prerequisite for the specific practices that allow genuine accuracy to be achieved despite the natural tendencies of the cognitive system. It requires the scout mindset as a sustained orientation: the genuine motivation to find out what is true rather than to defend what you already believe, maintained not as a performance but as the actual organising value of your intellectual life. This is harder than it sounds because it requires the repeated experience of changing your mind as a satisfying rather than a threatening event, which requires the prior work of separating your identity from your specific beliefs. It requires calibrated probabilistic thinking: the consistent practice of holding beliefs as probability estimates rather than as certainties, of making those estimates explicit enough to be tracked and evaluated over time, and of updating them proportionally and continuously in response to new information rather than catastrophically in response to social pressure or anchoring them against disconfirming evidence. It requires active disconfirmation seeking: the deliberate practice of looking for the strongest available case against your current position before strengthening your commitment to it, of identifying the assumptions that your conclusions most depend on and subjecting those assumptions to the most rigorous scrutiny available and of taking seriously the anomalies that your current frameworks cannot accommodate rather than explaining them away. It requires the domain-specific epistemic tools that allow the evaluation of the specific kinds of evidence that your professional context generates: the statistical claims, the data visualisations, the algorithmic outputs and the scientific-sounding assertions that require specific detection capabilities to evaluate rather than general reasoning skills. And it requires the social and moral dimensions that Jacobs identifies as the ones most consistently neglected by the cognitive account: the willingness to be genuinely moved by evidence and argument rather than performing openness while remaining defended, the courage to change your mind publicly when the evidence warrants it and the specific intellectual humility that comes from genuinely engaging with the strongest available versions of the positions you are most confident are wrong. What This Demands of You Specifically The synthesis of this body of work makes a specific demand that is more metacognitive than anything that came before it in this conversation. It asks you to turn the frameworks you have been building for understanding the world back on the mind that is doing the building. The most important single practice it demands is the regular explicit examination of your highest-confidence beliefs in your professional domain. Not the beliefs you hold tentatively and know need more evidence. The beliefs you hold most confidently, that feel most obviously true, that you would defend most readily against challenge. These are the beliefs most in need of the scout mindset’s scrutiny precisely because they are the ones the soldier mindset is most powerfully protecting. The specific question to apply to each: what would have to be true for this to be wrong and is any of that actually true? Not as a performance of open-mindedness. As a genuine epistemic practice applied with the same rigour you would apply to evaluating someone else’s analysis of the same question. The answer will sometimes be nothing would have to be true because this belief is genuinely well-founded. That is a legitimate outcome and it strengthens the belief appropriately. More often the answer will reveal an assumption, a gap in the evidence or a framework dependency that was previously invisible precisely because the confidence in the conclusion made it unnecessary to examine. That revelation, uncomfortable as it consistently is, is what genuine critical thinking actually produces. Not the satisfying confirmation of what you already thought. The specific, actionable and intellectually honest awareness of where your current thinking is most vulnerable to being wrong. That awareness, sustained across a career of consequential decisions, is the difference between wisdom and the mere accumulation of sophisticated confidence. It is entirely worth developing. This is a public episode. If you would like to discuss this with other subscribers or get access to bonus episodes, visit tiwaryshailesh.substack.com