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Jul 30, 2026
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Links For July 2026 (Part 2)

39 min • 5,973 words • 305 comments • 150 likes
Scott's monthly links roundup covering AI progress, the coming flood of philanthropic funding to effective altruism from AI companies, new research on persuasion and forecasting, and various scientific and cultural topics ranging from dementia prevention to Romanian politicians' embarrassing quotes. Longer summary
This is the second part of Scott Alexander's monthly links roundup for July 2026, covering a wide range of topics including AI developments, effective altruism funding waves, healthcare research, and cultural curiosities. Major themes include Chinese AI models catching up to the US (though still 6-12 months behind), the coming "third wave" of American philanthropy from AI company equity donations potentially flooding effective altruism with $40 billion/year, AI systems now outperforming humans at persuasion in specific contexts, and various scientific findings from dementia prevention to infinite ethics. The post maintains Scott's characteristic style of jumping between serious technical analysis, historical oddities, and humorous observations, with extensive linking to sources and ongoing debates in the rationalist and effective altruist communities. Shorter summary
Jul 22, 2026
acx
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Links For July 2026 (Part 1)

25 min • 3,748 words • 418 comments • 198 likes
Scott shares his monthly collection of interesting links from around the internet, covering topics from Jeremy Bentham's linguistic legacy to AI developments, with characteristic commentary and fact-checking caveats. Longer summary
This is Scott's monthly 'Links' post, a curated collection of interesting articles, studies, and social media posts from around the internet. The links span a wide range of topics including historical curiosities (Jeremy Bentham's word inventions, beard-wearing persecution in 19th century America), scientific oddities (a mushroom that causes gnome hallucinations), AI developments (mathematical proofs, constrained writing, dating apps), current events (Berkeley's housing permits, GLP-1 weight retention), and cultural phenomena (the Monet/AI art prank). Scott includes his typical epistemic disclaimers about not having verified all links independently and provides commentary throughout. The post ends with a note that he accumulated too many links and will publish the second half next week. Shorter summary
Jul 17, 2026
acx
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Your Book Review: Great And Desperate Cures

132 min • 20,439 words • 195 comments • 193 likes • podcast (147 min)
A review of 'Great and Desperate Cures' by Elliot Valenstein, which examines the history of lobotomy and psychosurgery, explaining how tens of thousands of patients underwent dangerous brain operations from the 1930s-1950s despite poor evidence of effectiveness. Longer summary
The post reviews 'Great and Desperate Cures' (1986) by psychologist Elliot Valenstein, exploring how lobotomy became widespread despite its horrific consequences. The review details the procedure itself (inserting an ice-pick-like instrument through the eye socket into the brain), then examines six factors Valenstein identifies for its acceptance: desperate patients and families, physician ambition (especially Egas Moniz and Walter Freeman), uncritical acceptance by researchers and media, territorial disputes between medical specialties, and cold economics. The post includes extensive details about key figures, particularly Freeman's aggressive promotion of transorbital lobotomy and his traveling surgery roadshows. It discusses patient outcomes, the lack of theoretical justification, media hype, and the procedure's eventual replacement by psychoactive drugs. The review concludes by reflecting on modern parallels and the tragic story of Howard Dully, lobotomized at age twelve, arguing that while Freeman likely had good intentions, the safeguards that might have prevented such harm were inadequate then and remain concerning today. Shorter summary
Jun 23, 2026
acx
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Should People Avoid Whole-Body Screening Info?

30 min • 4,501 words • 355 comments • 269 likes • podcast (25 min)
Scott analyzes whether whole-body screening MRIs are worth it by doing a detailed cost-benefit calculation, finding they cost about $108,000 per quality-adjusted life-year saved (right around the threshold of cost-effectiveness), and argues that while rich people immune to anxiety might benefit, most people claiming to be rational about medical decisions probably aren't. Longer summary
Scott performs a detailed cost-benefit analysis of whole-body screening MRIs in response to controversy over medical experts recommending against them. Using rough order-of-magnitude estimates, he calculates that screening 1,000 people saves about 32 quality-adjusted life-years (QALYs) at a cost of $2.7 million plus time and anxiety costs, working out to about $108,000 per QALY saved—right at the threshold of cost-effectiveness. He explores whether rich people who don't care about money should get screened, finding a plausible case but with many caveats about unknown factors that could swing the calculation either way. He then applies this analysis to Midjourney's proposed ultrasound scanner, finding it's unlikely to be clearly better than MRI. The post ends with a warning that people who think they're rational enough to ignore false positives are often the same people making irrational medical decisions based on contrarian appeals. Shorter summary
Jun 16, 2026
acx
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Never Cross a River Four Feet Deep on Average

45 min • 6,939 words • 115 comments • 189 likes • podcast (38 min)
A replication of a 2023 neuroscience study on brain entrainment and learning found that the original effect likely doesn't exist, revealing how the study obscured key issues through statistical averaging and highlighting how AI tools are democratizing scientific scrutiny. Longer summary
Sasha Putilin received an ACX grant to replicate a 2023 study claiming that flickering lights synchronized to individual brain rhythms could boost learning speed threefold. The $32,000 replication with 12 participants (versus 80 in the original) found no such effect. Upon examining the original data more closely, Putilin discovered the apparent effect was driven entirely by a few participants with large negative learning rates (getting worse over time) who happened to all be in one experimental group. The original study had obscured this pattern by presenting averaged data rather than individual results. Putilin argues this exemplifies 'cargo-cult statistics' where researchers mechanically apply statistical rituals without critically examining underlying data. The post concludes by suggesting AI tools are democratizing meta-science, enabling anyone to audit published research that previously required expert-level effort. Shorter summary
Feb 18, 2026
acx
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Record Low Crime Rates Are Real, Not Just Reporting Bias Or Improved Medical Care

17 min • 2,566 words • 718 comments • 388 likes • podcast (17 min)
Scott demonstrates that US crime rates are at historic lows using multiple data sources, then debunks the theories that this is due to reporting bias or improved medical care, before briefly discussing possible explanations for the decline. Longer summary
Scott presents evidence that US crime rates, particularly murder rates, are at or near historic lows, then systematically debunks two common objections: that the decline is due to underreporting bias, and that it's an artifact of improved medical care saving would-be murder victims. He shows that multiple independent data sources (including victim surveys and consistently-reported crimes like car theft) confirm the decline, and that while medical care has improved, gun injuries have become more severe at roughly the same rate, canceling out the effect. The post concludes by listing various theories for why crime has declined and questioning why public perception doesn't match the data. Shorter summary
Jan 13, 2026
acx
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Mantic Monday: The Monkey's Paw Curls

42 min • 6,449 words • 247 comments • 211 likes • podcast (36 min)
Scott reviews the state of prediction markets after explosive growth, finding that most volume is degenerate sports gambling rather than useful forecasting, and proposes both technical solutions and two potential futures for the field. Longer summary
Scott Alexander examines the current state of prediction markets after their recent explosion in popularity, noting that while volume has grown from millions to billions per month, most of it comes from sports betting rather than the epistemic improvement he'd hoped for. He explores several problems: markets aren't asking the most important questions society needs answered; resolution criteria disputes ("rulescucking") create controversy; and there are concerns about insider trading and manipulation. He proposes solutions including a novel approach to conditional markets and suggests two paths forward: either creating user-generated, subjectively-resolved real-money markets (the "Siskind Cube"), or accepting that prediction markets' main value may be as training data for AI forecasters that could make the markets themselves obsolete by late 2026. Shorter summary
Oct 30, 2025
acx
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Links For October 2025

42 min • 6,423 words • 803 comments • 211 likes • podcast (38 min)
Scott Alexander presents 51 links covering AI progress and safety, political developments, scientific research, cultural oddities, and ongoing philosophical debates about miracles and education reform. Longer summary
Scott Alexander shares 51 links covering diverse topics including AI developments (agents, safety, consciousness research), political news (Ukraine policy, UK politics, Trump administration), science updates (climate predictions, genetics, bacteriophages), cultural curiosities (Shakespeare superfan plastic surgery, Soviet naming conventions, flag cones), health research (Alzheimer's prevention, shingles vaccine reducing dementia, kidney donation), and philosophical debates (Hume's argument against miracles, the Fatima miracle discussion). The post maintains Scott's characteristic blend of serious analysis and quirky observations, touching on everything from Bach's descendants in Oklahoma to the mystery of why AI still struggles with laundry folding despite mastering protein folding. Shorter summary
Oct 01, 2025
acx
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The Fatima Sun Miracle: Much More Than You Wanted To Know

213 min • 32,949 words • 755 comments • 679 likes • podcast (186 min)
A detailed investigation of the Sun Miracle of Fatima in 1917, where 70,000 people witnessed the sun appear to spin, change colors, and fall to earth, analyzing witness testimonies, skeptical explanations, and similar phenomena at other Marian apparition sites. Longer summary
Scott conducts an extensive investigation into the 1917 Miracle of the Sun at Fatima, where tens of thousands witnessed what appeared to be the sun spinning, changing colors, and falling to earth. He examines approximately 60 primary testimonies, evaluates common skeptical explanations (optical phenomena, weather events, mass hallucination), and documents similar sun miracles at other Marian apparition sites worldwide. Scott then critiques Dalleur's theory about distant witnesses and shadow analysis, explores why more people don't see these phenomena normally, and proposes a tentative materialist explanation involving a rare optical illusion modulated by cloud cover and social priming. The post ends by suggesting research directions for those interested in further investigation. Shorter summary
Jul 31, 2025
acx
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Suddenly, Trait-Based Embryo Selection

56 min • 8,637 words • 748 comments • 407 likes • podcast (60 min)
Scott analyzes the sudden emergence of commercial trait-based embryo selection services, discussing both the scientific validity and ethical implications of selecting embryos for health outcomes, intelligence, and physical traits. Longer summary
Scott examines the recent development of commercial embryo selection services, particularly focusing on companies like Genomic Prediction, Orchid Health, Nucleus, and Herasight. He explains how the technology works, comparing different companies' claims and methodologies, and discusses both scientific challenges and ethical concerns. The post explores the potential benefits, like reduced disease risk and increased IQ, while acknowledging issues around cost, racial disparities, and social implications. A significant portion focuses on Herasight's critique of competitor Nucleus's scientific claims. The post concludes by placing this technology in the broader context of human enhancement and future technological developments. Shorter summary
Jul 11, 2025
acx
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Your Review: Of Mice, Mechanisms, and Dementia

51 min • 7,754 words • 170 comments • 183 likes • podcast (48 min)
A detailed review of a 1995 paper introducing the PDAPP mouse model for Alzheimer's disease, examining how its limitations were overlooked and shaped decades of potentially misguided Alzheimer's research. Longer summary
The post reviews a landmark 1995 paper introducing the PDAPP mouse model for Alzheimer's disease, analyzing how its technical achievements and limitations shaped three decades of Alzheimer's research. The author examines the paper's methodology, results, and claims, showing how the model's flaws - including extreme protein overexpression and lack of key disease features - were overlooked in favor of a compelling but incomplete amyloid cascade hypothesis, leading to years of failed drug development and missed opportunities to explore alternative approaches. Shorter summary
Jul 04, 2025
acx
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Your Review: School

55 min • 8,460 words • 553 comments • 434 likes • podcast (46 min)
This review explores how schools are primarily designed to maximize motivation rather than learning, explaining why age-graded classrooms and seemingly inefficient group learning have persisted despite numerous attempts at reform. Longer summary
The post examines why schools have maintained their traditional structure of age-graded classrooms where all students learn the same content, despite its apparent inefficiencies. The author argues that schools are designed primarily to maximize motivation rather than learning, using conformity as a key tool. Through analyzing various attempts at personalized learning and their consistent failures to scale beyond about 5% of students, the post explains how students fall into three categories: no-structure learners, low-structure learners, and high-structure learners. The author concludes that while the current system is far from perfect, it has proven more effective at scale than any alternatives, predicting that despite continued attempts at reform, the basic structure of schooling will remain unchanged. Shorter summary
Jul 03, 2025
acx
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Highlights From The Comments On Missing Heritability

66 min • 10,199 words • 134 comments • 94 likes • podcast (61 min)
Scott Alexander responds to comments and criticism on his earlier post about 'Missing Heritability', discussing issues like gene-environment interactions, sequencing technology limitations, and the use of polygenic scores across ancestry groups. Longer summary
This post compiles and responds to notable comments on Scott's earlier post about 'Missing Heritability'. The post is structured in four sections, starting with responses from experts named in the original post, particularly Sasha Gusev who critiques the treatment of gene-environment interactions and cross-population polygenic scores. The second section features detailed technical comments from knowledgeable readers about topics like genetic interactions and sequencing technology limitations. The third section addresses specific corrections to the original post, while the final section covers various other interesting comments and discussions. Throughout, Scott engages with the criticisms and new perspectives while maintaining his original position on most key points. Shorter summary
Jul 01, 2025
acx
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Links For July 2025

28 min • 4,200 words • 581 comments • 210 likes • podcast (32 min)
Scott shares his monthly collection of 56 interesting links and developments from July 2025, covering AI, politics, science, and culture, with brief commentary on each. Longer summary
This is a collection of 56 interesting links and news items from July 2025, covering topics from AI development to politics to scientific research. The post includes updates on OpenAI's status, developments in AI regulation, new medical treatments, cultural trends, and various scientific findings. Scott maintains his usual style of presenting these with brief commentary and occasional humor, while being careful to note that he hasn't independently verified all links. Some notable items include Trump's "Big Beautiful Bill", new AI safety developments, trends in social media usage, and various medical breakthroughs. Shorter summary
Jun 30, 2025
acx
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Contra Skolnick On Schizophrenia Microbes

11 min • 1,619 words • 180 comments • 256 likes • podcast (11 min)
Scott Alexander refutes Stephen Skolnick's theory that schizophrenia is caused by gut microbes rather than genetics, showing why the evidence better supports schizophrenia being a complex genetic neurodevelopmental disorder. Longer summary
Scott Alexander responds to Stephen Skolnick's theory that schizophrenia is caused by gut microbes rather than genetics. He systematically dismantles Skolnick's arguments by showing that twin concordance rates are exactly what we'd expect from a genetic condition, that microbiological inheritance patterns don't match schizophrenia inheritance patterns, and that the gut bacteria evidence cited was likely caused by antipsychotic medication rather than being causative. He concludes by explaining why schizophrenia is best understood as a complex neurodevelopmental disorder with multiple contributing factors rather than having a single cause. Shorter summary
Jun 26, 2025
acx
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Missing Heritability: Much More Than You Wanted To Know

68 min • 10,491 words • 669 comments • 456 likes • podcast (62 min)
Scott explores the 'missing heritability' problem in genetics, where twin studies show traits like IQ and educational attainment are highly heritable but newer genomic methods find much lower heritability, analyzing various potential explanations for this discrepancy. Longer summary
The post examines the 'missing heritability' problem in genetics, where twin studies consistently show behavioral traits like IQ and educational attainment are substantially heritable (around 40-60%), while newer genomic methods find much lower heritability (around 15-20%). Scott reviews the history of behavioral genetics research, explains various study methodologies and their potential biases, and analyzes different hypotheses for this discrepancy. He examines whether twin studies might be flawed, whether newer methods might be missing important genetic effects, and whether educational attainment might be an unusually problematic trait to study. While acknowledging remaining mysteries, he tentatively concludes that twin studies are probably largely correct and that newer methods may be missing rare variants and genetic interactions. Shorter summary
Jun 18, 2025
acx
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ACX Grants 1-3 Year Updates

83 min • 12,838 words • 169 comments • 124 likes • podcast (75 min)
Scott reviews updates from two cohorts of ACX Grants recipients (from 2021 and 2024), analyzing their progress and sharing lessons learned about what makes grants successful. Longer summary
Scott Alexander reviews progress updates from two cohorts of ACX Grants recipients - the first cohort from 2021 (after 3 years) and the second from 2024 (after 1 year). The post methodically goes through each grant's status, with many showing significant progress in areas like AI safety advocacy, animal welfare, scientific research, and political lobbying. Scott then analyzes patterns in what made grants successful, finding that lobbying organizations and animal welfare projects were particularly effective, while scientific grants were harder to evaluate. He concludes that while not all projects succeeded, the $3 million program generated good value through both direct impact and startup creation, and he plans to continue it with some adjustments. Shorter summary
Mar 07, 2025
acx
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Why Should Intelligence Be Related To Neuron Count?

10 min • 1,533 words • 214 comments • 291 likes • podcast (10 min)
Scott investigates the correlation between intelligence and neuron count, exploring various theories before suggesting that more neurons allow for less polysemantic (overlapping) representations of concepts. Longer summary
Scott explores why intelligence correlates with neuron count across species, humans, and AI models, despite this correlation not being immediately intuitive. He examines various hypotheses about how having more neurons could help with complex pattern-matching tasks like IQ tests. After discussing several possibilities including pattern storage and matching, he settles on polysemanticity as a potential explanation: fewer neurons means each neuron must encode multiple concepts, reducing precision. The post concludes with insights from an expert suggesting that larger neural networks (biological or artificial) can better approximate complex functions and maintain multiple hypotheses simultaneously. Shorter summary
Feb 07, 2025
acx
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1DaySooner's Trump II Health Policy Proposals

13 min • 1,950 words • 269 comments • 234 likes • podcast (12 min)
Scott Alexander and 1DaySooner outline potential positive health policy initiatives that could emerge under three key Trump administration health appointees: Jim O'Neill, Marty Makary, and Jay Bhattacharya. Longer summary
This post discusses potential health policy proposals under a hypothetical second Trump administration, focusing on three key appointees and their possible initiatives. The piece examines Jim O'Neill as Deputy Secretary of HHS, highlighting his potential work on organ donation compensation and longevity research; Marty Makary as FDA Commissioner, discussing FDA transparency and regulatory improvements; and Jay Bhattacharya as NIH Director, exploring research funding reforms and challenge trials. Written in collaboration with 1DaySooner, the post specifically focuses on optimistic scenarios that could emerge from these appointments. Shorter summary
Jan 15, 2025
acx
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How To Stop Worrying And Learn To Love Lynn's National IQ Estimates

10 min • 1,517 words • 813 comments • 525 likes • podcast (10 min)
Scott Alexander examines Richard Lynn's controversial national IQ estimates and argues they are actually consistent with environmental rather than genetic explanations of IQ differences, while explaining common misconceptions about what low IQ means. Longer summary
Scott Alexander discusses Richard Lynn's controversial national IQ estimates, which show very low IQs in some countries like Malawi. The post addresses two main objections: that such estimates are racist, and that they seem to contradict common sense observation. Scott argues that Lynn's findings are actually more consistent with anti-racist environmental explanations of IQ differences than with genetic ones, given the huge gaps in nutrition, healthcare and education. He then explains why normal people with low IQ appear more functional than those with similar IQs due to specific syndromes, since the latter have additional deficits beyond just low IQ. The post concludes that Lynn's data suggests room for optimism about the potential impact of developmental interventions. Shorter summary
Dec 10, 2024
acx
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Highlights From The Comments On Prison

67 min • 10,235 words • 571 comments • 233 likes • podcast (56 min)
Scott summarizes and responds to reader comments on his prison effectiveness analysis, covering topics like criminal psychology, policing, El Salvador's crime reduction, probation issues, and proposed alternatives to imprisonment. Longer summary
This post summarizes and responds to reader comments on Scott's previous analysis of prison effectiveness, covering several key areas. Commenters discuss criminal psychology and the role of time discounting, policing practices and staffing challenges, the timeline of El Salvador's crime reduction, issues with probation as an alternative to prison, and various proposed solutions. Scott particularly engages with comments about whether his analysis missed important factors like in-prison crime and eugenic effects, and reflects on the moral philosophy of punishing criminals. Shorter summary
Nov 27, 2024
acx
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Prison And Crime: Much More Than You Wanted To Know

97 min • 15,033 words • 874 comments • 601 likes • podcast (88 min)
Scott analyzes research on whether longer prison sentences reduce crime, examining studies on deterrence, incapacitation, and aftereffects, to conclude that while prison does decrease crime through incapacitation, it's less cost-effective than other methods like policing. Longer summary
This post examines the relationship between prison sentences and crime reduction through three mechanisms: deterrence (scaring potential criminals), incapacitation (preventing prisoners from committing crimes), and aftereffects (post-release behavior changes). Through analysis of multiple studies and reviews, Scott finds that deterrence effects are minimal, incapacitation has strong positive effects (preventing about 7 crimes per prisoner-year), and aftereffects range from slightly beneficial to harmful depending on circumstances. He concludes that while prison does reduce crime, with a 10% increase in incarceration reducing crime by about 3%, it's less cost-effective than alternatives like increased policing. The post ends by examining practical challenges in the justice system that prevent effective handling of repeat offenders. Shorter summary
Nov 22, 2024
acx
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Against The Generalized Anti-Caution Argument

14 min • 2,033 words • 499 comments • 396 likes • podcast (12 min)
Scott Alexander explains why dismissing warnings just because previous similar warnings were wrong is a dangerous fallacy, particularly for risks that naturally increase over time. Longer summary
Scott Alexander criticizes what he calls the "generalized anti-caution argument" - the tendency to dismiss warnings about risks because previous similar warnings didn't come true. He explains that for gradually increasing risks (like drug doses or AI capabilities), being wrong about earlier warnings doesn't invalidate later ones. He illustrates this through several examples including the Ukraine war, Biden's cognitive decline, and AI development, contrasting these with cases where the risk doesn't naturally increase over time. The post ends by arguing that people should maintain appropriate caution even after false alarms, particularly for risks that naturally increase over time. Shorter summary
Nov 01, 2024
acx
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Links For November 2024

42 min • 6,373 words • 932 comments • 216 likes • podcast (41 min)
A diverse collection of news items, studies, and interesting facts from November 2024, covering topics from scientific discoveries to cultural phenomena. Longer summary
This post is a compilation of various news items, studies, and interesting facts from November 2024. It covers a wide range of topics including scientific discoveries, political events, technological advancements, cultural phenomena, and historical anecdotes. The post is structured as a numbered list, with each item briefly summarizing a piece of news or information. Some notable items include a new schizophrenia drug approval, YouGov polling results on various historical figures, findings on genetic IQ changes over time, and updates on AI technology and its implications. Shorter summary
Sep 06, 2024
acx
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Your Book Review: The Pale King

45 min • 6,959 words • 283 comments • 237 likes • podcast (46 min)
A review of David Foster Wallace's 'The Pale King', examining its themes, the author's style and personal struggles, and the reviewer's evolving perspective on Wallace's work and legacy. Longer summary
This book review discusses David Foster Wallace's unfinished novel 'The Pale King', focusing on its themes, Wallace's writing style, and his personal struggles. The review explores Wallace's attempt to transcend postmodernism, his critique of consumer culture, and his vision for a more sincere and morally engaged society. It also delves into Wallace's mental health issues, his suicide, and the posthumous controversy surrounding his personal life. The reviewer reflects on their own journey with Wallace's work, from initial admiration to eventual disillusionment, while still acknowledging the value and limitations of his literary contributions. Shorter summary
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