Notes - Deep Work

June 25, 2025

Chapter 1: Deep Work Is Valuable

This chapter posits that deep work—professional activities performed in a state of distraction-free concentration that push cognitive capabilities to their limit, creating new value, improving skill, and being hard to replicate—is crucial for thriving in the modern economy.

How to Become a Winner in the New Economy

The chapter introduces three groups that are poised to succeed in the "Great Restructuring" of the economy, as described by MIT economists Erik Brynjolfsson and Andrew McAfee in Race Against the Machine:

• The High-Skilled Workers: Individuals who are adept at working with and extracting valuable results from increasingly complex intelligent machines, such as Nate Silver, who mastered statistical analysis systems like Stata and database languages like SQL to predict election outcomes. Their value increases as technology augments abstract and data-driven reasoning.
• The Superstars: Those who are among the best at what they do, like David Heinemeier Hansson, creator of Ruby on Rails. High-speed data networks and collaboration tools have created "winner-take-all" markets, where consumers choose the very best, even if their talent advantage is small, because talent is not a commodity that can be combined from mediocre parts. This means a small number of top performers capture the bulk of the market.
• The Owners: Individuals with capital to invest in new technologies, exemplified by venture capitalist John Doerr. As digital technology reduces the need for labor, a disproportionate amount of rewards flow to those who own the intelligent machines, making it a particularly advantageous time to have capital.

The author argues that while becoming an "owner" isn't generally accessible, the first two groups are, and the secret to joining them lies in two core abilities:

1. The ability to quickly master hard things. Since intelligent machines are complex and rapidly changing, continuous and fast learning is essential (e.g., mastering complex software like Stata's "generalized SEM and BLOBs").
2. The ability to produce at an elite level, in terms of both quality and speed. This involves transforming latent potential into tangible, valuable results that push current skills to their limit.

The central thesis of the book is that both these core abilities depend on your ability to perform deep work.

Deep Work Helps You Quickly Learn Hard Things

• The philosopher Antonin-Dalmace Sertillanges' advice to "Let your mind become a lens, thanks to the converging rays of attention" highlights that learning requires intense concentration.
• This is supported by K. Anders Ericsson's deliberate practice theory, which states that expert performance is achieved through "life-long deliberate effort to improve performance" rather than innate talent.
• The core components of deliberate practice are tightly focused attention on a specific skill and feedback for correction. Crucially, deliberate practice cannot exist alongside distraction.
• Neuroscience provides a physical mechanism: intense focus on a specific skill causes myelin (fatty tissue) to grow around relevant neurons, making the corresponding brain circuit fire faster and more effectively. Distracted learning prevents this "useful myelination" by firing too many circuits haphazardly. Therefore, learning hard things quickly is an act of deep work.

Deep Work Helps You Produce at an Elite Level

• Adam Grant, Wharton's youngest full professor, demonstrates elite productivity by batching his hard, intellectual work into long, uninterrupted stretches. For instance, he teaches in one semester to dedicate the other to deep research, and during research periods, he isolates himself for multiple days, using an out-of-office auto-responder to avoid interruptions.
• His productivity is explained by the formula: High-Quality Work Produced = (Time Spent) x (Intensity of Focus). By maximizing his focus, he maximizes output per unit of time.
• Sophie Leroy's "attention residue" theory explains why uninterrupted focus is crucial: when switching between tasks (Task A to Task B), a residue of attention remains stuck on Task A, dampening performance on Task B. This residue is especially thick if the prior task was low intensity or unbounded.
• Constant, quick checks of email or social media, even for a moment, introduce new "unfinished" tasks, creating attention residue and significantly hindering performance on the primary deep task.
• Thus, to produce at peak levels, one needs to work for extended periods with full concentration, free from distraction. Deep work is the type of effort that optimizes performance, enabling individuals to produce at the quality and quantity levels necessary to thrive professionally.

What About Jack Dorsey?

• The chapter addresses the argument that some successful individuals, like Jack Dorsey (co-founder of Twitter and Square), thrive without depth, characterized by highly fractured schedules filled with meetings and constant communication.
• The author argues that this "specificity" of high-level executive roles is important: CEOs are "hard-to-automate decision engines" whose value lies in processing inputs and making rapid decisions, not in prolonged deep thought. Their behavior cannot be extrapolated to other jobs.
• While some jobs (e.g., certain sales, lobbying) inherently require constant connection, many knowledge workers mistakenly believe their roles preclude deep work.
• Examples like management consultants who improved performance by reducing constant connectivity, and managers adopting structured communication methods (e.g., Scrum) to free up thinking time, demonstrate that even seemingly shallow-driven jobs can benefit from prioritizing depth.
• The conclusion is that deep work is not the only valuable skill, but the niches where it's not advisable are increasingly rare. Unless there is strong evidence that constant distraction is essential for a specific profession, prioritizing depth is beneficial.

Chapter 2: Deep Work Is Rare

This chapter delves into why deep work is a rare commodity in today's business environment, despite its growing value. It identifies several prevalent trends and cultural mindsets that hinder deep work.

Introduction to Rarity

• Modern business trends like open office plans (e.g., Facebook, Square's headquarters), the rise of instant messaging (e.g., IBM, Hall), and the pressure for social media presence (e.g., New York Times journalists like Alissa Rubin being encouraged to tweet) actively decrease the ability to go deep.
• Open offices cause "massive distraction". Instant messaging magnifies interruptions. Social media forces journalists to interrupt serious work for "frothy back-and-forth online tittering".
• This creates a paradox: deep work is increasingly valuable, yet organizations prioritize trends that undermine it. The reasons for this widespread embrace of distraction are often arbitrary and based on flawed thinking.

The Metric Black Hole

• The impact of distraction and depth on a business's bottom line is difficult to measure. Tom Cochran's experiment at Atlantic Media, for example, found the company spent over a million dollars annually on email processing, yet even this extensive calculation didn't fully capture the true costs or benefits.
• This difficulty creates a "metric black hole," where the negative consequences of depth-destroying behaviors are not easily quantified.
• Without clear metrics, business behaviors are susceptible to "unstable whim and shifting forces," allowing distracting practices to flourish.

The Principle of Least Resistance

• This principle states: "In a business setting, without clear feedback on the impact of various behaviors to the bottom line, we will tend toward behaviors that are easiest in the moment.".
• The pervasive culture of connectivity (e.g., expecting immediate email responses) persists because it feels "easier" in the short term, allowing for quick answers and managing the day from the inbox, avoiding the need for advanced planning.
• Leslie Perlow's study at Boston Consulting Group demonstrated that forcing consultants to take one day off per week from connectivity actually improved their well-being, productivity, communication, and client product quality, despite initial fears of negative impact. This suggests the perceived necessity of constant connectivity is often a convenience, not a requirement.
• Other depth-reducing behaviors supported by this principle include regularly occurring meetings (which serve as a "blunt form of personal organization" rather than efficient progress) and vague, open-ended "Thoughts?" emails (which are easy for the sender but burdensome for recipients). These behaviors save short-term discomfort but sacrifice long-term value and satisfaction.

Busyness as a Proxy for Productivity

• Unlike professions with clear metrics (e.g., a professor's h-index), many knowledge workers lack objective indicators of their productivity.
• To address this ambiguity, many resort to an industrial-age definition of productivity: "doing lots of stuff in a visible manner.". This mind-set makes constant email, frequent meetings, and active instant messaging seem crucial for demonstrating value.
• Yahoo CEO Marissa Mayer's ban on working from home, based on employees not "logging in enough," exemplifies punishing for a lack of "visible busyness".
• However, knowledge work's value often conflicts with busyness. Adam Grant's success, for instance, came from isolating himself for deep concentration, the opposite of public busyness. This "anachronistic" concept persists due to the metric black hole.

The Cult of the Internet

• Society operates under a "technopoly," as termed by Neil Postman, where new technology is assumed to be good and necessary, with alternatives becoming "invisible and therefore irrelevant".
• Evgeny Morozov calls "the Internet" an "uber-ideology," where embracing its tools is seen as being with the times. This Internet-centrism leads to depth-destroying behaviors, like active social media presence, being lauded, while avoiding them is seen as "out of touch".
• Deep work struggles in a technopoly because it values old-fashioned concepts like quality and craftsmanship and often requires rejecting high-tech distractions. The lack of clear metrics (the metric black hole) prevents objective evaluation of this shift.

Bad for Business. Good for You.

• The combined effect of the "Principle of Least Resistance," "Busyness as Proxy for Productivity," and "The Cult of the Internet"—all enabled by the "Metric Black Hole"—leads businesses to miss out on significant value production.
• However, this widespread "myopia" creates a "massive economic and personal opportunity" for individuals who recognize the trend and prioritize depth, as it becomes increasingly rare and valuable.

Chapter 3: Deep Work Is Meaningful

This chapter argues that deep work is not merely economically beneficial but also profoundly contributes to a fulfilling and meaningful life. It explores this connection from neurological, psychological, and philosophical perspectives.

A Neurological Argument for Depth

• Science writer Winifred Gallagher's book Rapt, inspired by her cancer diagnosis, proposes a "grand unified theory" of the mind: "Who you are, what you think, feel, and do, what you love—is the sum of what you focus on.".
• This means our brains construct our worldview based on our attention. Focusing on important things, and ignoring negative shallow ones, leads to experiencing work and life as more meaningful and positive.
• Deep concentration also "hijacks your attention apparatus," preventing you from dwelling on the numerous "smaller and less pleasant things" (e.g., irritating emails, office politics) that constantly vie for attention in knowledge work.
• A workday dominated by shallow concerns can be "draining and upsetting," as the "idle mind is the devil's workshop," leading to focus on what could be wrong in life.
• Therefore, increasing time in a state of depth leverages the brain's machinery to maximize meaning and satisfaction in one's working life.

A Psychological Argument for Depth

• Mihaly Csikszentmihalyi's "flow" theory suggests that "The best moments usually occur when a person’s body or mind is stretched to its limits in a voluntary effort to accomplish something difficult and worthwhile".
• Through his "experience sampling method (ESM)," Csikszentmihalyi found that people are often happier at work than during leisure, because jobs provide inherent goals, feedback, and challenges that encourage deep involvement. More flow experiences correlate with higher life satisfaction.
• Deep work is an ideal activity to generate a flow state as it involves intense concentration and pushing cognitive limits.
• Thus, building one's working life around the flow experience produced by deep work is a proven path to deep satisfaction.

A Philosophical Argument for Depth

• Philosophers Hubert Dreyfus and Sean Dorrance Kelly, in All Things Shining, argue that modern secular culture, influenced by Descartes and the Enlightenment, has stripped the world of inherent "sacredness" and meaning, leading to a sense of "nihilism".
• They propose craftsmanship as a key to restoring meaning. A craftsman, like Ric Furrer (a blacksmith), finds meaning not by arbitrarily assigning it, but by cultivating "the skill of discerning the meanings that are already there" in the materials and task. This external source of meaning frees the craftsman from subjective nihilism.
• This concept applies to knowledge work: any pursuit requiring high levels of skill, whether physical or cognitive (e.g., computer programming, writing, law), can generate this same sense of sacredness and meaning.
• The specifics of the job are less important than the "rarified approach" to the work, emphasizing skill and appreciation inherent in the craft.
• Cultivating craftsmanship necessarily requires deep work to hone and apply skills at an elite level. Therefore, embracing deep work can transform a knowledge work job into something deeply satisfying, "a portal to a world full of shining, wondrous things".

Homo Sapiens Deepensis

• This section concludes Part 1 by stating that deep work is pragmatically valuable and rare, creating a market opportunity.
• More profoundly, it asserts that neurological, psychological, and philosophical perspectives all converge on the idea that depth is intrinsically linked to meaning and human flourishing, leading to the concept of Homo sapiens deepensis (a species that thrives in depth and struggles in shallowness).
• The overarching message of Part 1 is that "A deep life is a good life, any way you look at it.".

Chapter 4: Drain the Shallows

This chapter provides practical strategies to reduce shallow work, enabling more time and energy for the deep efforts that are most impactful, acknowledging that while shallow work cannot be entirely eliminated, its negative footprint can be minimized.

Introduction to Draining the Shallows

• The example of 37signals (now Basecamp), a software company that moved to a four-day workweek (May-October) without losing productivity, illustrates that reducing work hours disproportionately eliminates shallow work, making employees more efficient with their limited time.
• Further, giving employees a month off for self-directed "deep work" projects (e.g., the month of June) generated valuable innovations that would not have occurred otherwise, proving that eliminating shallow work can significantly boost overall value.
• The core insight is that shallow work is "less vital than it often seems," and by culling it, more time becomes available for deep work, which truly matters.
• Limitations: Some shallow work is inevitable, and deep work is cognitively exhausting, with experts typically limited to around four hours of deep work per day. The goal, therefore, is to confine shallow work so it doesn't impede the bounded deep efforts. Many typical workdays are fragmented by meetings and other scheduled events, making it difficult to achieve even four hours of deep work without actively draining the shallows.

Schedule Every Minute of Your Day

• People often misestimate how they spend their time, operating on "autopilot".
• Strategy: Schedule every minute of your workday. At the start of each day, divide hours into specific blocks for activities (minimum 30 minutes, batching small tasks).
• Key: If the schedule is disrupted by bad estimates or interruptions, immediately create a revised schedule for the rest of the day. The goal is "thoughtful say in what you’re doing with your time going forward," not rigid adherence.
• Tactics for stability:
  1. Accurately estimate time needed for tasks.
  2. Use overflow conditional blocks to build flexibility into the schedule.
  3. Be liberal with task blocks for unexpected items.
• This method encourages creativity by ensuring dedicated blocks for grappling with new ideas and challenging work, while allowing for spontaneous deviations when innovative insights strike. It forces respect for time and fosters organization.

Quantify the Depth of Every Activity

• To accurately categorize tasks as shallow or deep, ask: "How long would it take (in months) to train a smart recent college graduate with no specialized training in my field to complete this task?".
• Many months indicate a deep task (leveraging hard-won expertise, e.g., editing an academic paper requiring years of specialized knowledge).
• Quick learning (e.g., a few weeks or months for a PowerPoint presentation or attending a planning meeting that's mostly small talk/posturing) indicates a shallow task (does not leverage expertise).
• Once activities are quantified, bias your time toward deep tasks, as they provide higher value and skill improvement, while minimizing shallow ones.

Ask Your Boss for a Shallow Work Budget

• Strategy: Initiate a conversation with your boss (or yourself) to agree on a specific percentage of time to be spent on shallow work (typically 30-50% for non-entry-level roles).
• Adhering to this budget will force you to say no to shallow projects and streamline existing ones (e.g., reducing unnecessary meetings, being less immediate with email responses).
• This agreement provides "implicit support" or "cover" from the workplace, allowing you to justify your choices by stating they are necessary to meet your agreed-upon deep-to-shallow ratio.
• For self-employed individuals, this exercise clarifies how little actual value is produced by excessive shallow work, providing the confidence to scale back and reinvest time in high-impact activities.
• If the answer from a boss indicates a job requires 100% shallow work, it signifies the job is not conducive to deep work, prompting a search for a new position.

Finish Your Work by Five Thirty (Fixed-Schedule Productivity)

• This is a "meta-habit" where you set a firm, fixed end-time for your workday (e.g., 5:30 p.m.) and then work backward to implement productivity strategies that allow you to meet this deadline.
• The author, a professor, uses this method to maintain high academic productivity despite avoiding evening and weekend work, a rarity in his field.
• Radhika Nagpal, a Harvard professor, also successfully used this strategy by limiting her workweek to fifty hours and setting "drastic quotas" on shallow activities like travel and paper reviews.
• This strategy forces a "scarcity mind-set": time becomes precious, making any obligation beyond deep efforts suspect. The default response shifts to "no," and tasks that pass this filter are tackled with "ruthless efficiency".
• It also forces more careful time management and organization, leading to greater value production compared to longer, less organized schedules. This strategy can also reveal that many presumed expectations for immediate responses (e.g., evening emails from a boss) are not actually required.

Become Hard to Reach

This section offers three tips to regain control over electronic communication, especially email.

• Tip #1: Make People Who Send You E-mails Do More Work (Sender Filter).
  • Instead of a general email address, provide specific contacts for specific purposes, or a special-purpose email address with conditions (e.g., "interesting@calnewport.com") and a low expectation of a response.
  • This filters out trivial or demanding requests and resets correspondent expectations so that an overflowing inbox no longer generates a sense of obligation.
  • Examples include Clay Herbert's FAQ and survey filter, or Antonio Centeno's "promises" before allowing a message. This strategy is particularly useful for those who can dictate their accessibility.
• Tip #2: Do More Work When You Send or Reply to E-mails (Process-Centric Approach).
  • Before replying, identify the "project represented by this message" and the "most efficient (in terms of messages generated) process for bringing this project to a successful conclusion".
  • Craft a response that clearly describes this process, points out the current step, and emphasizes the next. This minimizes the total number of emails in a conversation and "closes the loop" on projects immediately, reducing mental clutter.
  • While it takes more effort upfront, it saves much more time and mental energy later.
• Tip #3: Don’t Respond (Professorial E-mail Sorting).
  • Inspired by famous academics, the default is not to respond if the sender doesn't make a convincing case that a reply is worthwhile and minimizes the effort required.
  • Three rules for sorting: Do not reply if the message is:
    1. Ambiguous or hard to generate a reasonable response for.
    2. Not a question or proposal that interests you.
    3. Such that nothing good would happen if you respond, and nothing bad would happen if you don’t.
  • This approach, though initially uncomfortable as it breaks social conventions, reduces the number of emails sent and ignored, significantly weakening email's "grip" on time and attention, and freeing up resources for deeper work. It aligns with the principle of "letting small bad things happen" to make time for "life-changing big things".