The Entropy Mental Model
Disorder is the default; order requires constant energy investment
Entropy is the second law of thermodynamics applied as a mental model for life, business, and relationships. The core principle is startlingly simple: disorder is not a mistake; it is the default. Order is always artificial and temporary. Everything naturally tends toward chaos -- your house gets messy, relationships weaken, skills decay, businesses bureaucratize, and knowledge is forgotten. This is not because something went wrong but because entropy is the universe's tax on time.
Understanding entropy transforms how you allocate energy. Instead of being surprised when things fall apart, you expect it and build maintenance systems to counteract it. The framework distinguishes between passive stability (a well-designed ship sailing through a storm without intervention) and active stability (a fighter jet requiring constant adjustment or it crashes). Most important things in life -- relationships, health, skills, organizations -- require active stability, yet people often treat them as if they were passively stable, leading to eventual collapse.
- Disorder is not a mistake; it is the default. Order is always artificial and temporary
- Entropy is the universe's tax on time -- you must pay energy just to maintain current state
- The harder it is to keep something simple, the more entropy is at work
- The higher the entropy in a system, the less efficient any energy you apply will be
- For a change to occur, you must apply more energy than is extracted by the system
- Identify What Requires Active vs Passive StabilityAudit the important domains of your life: relationships, health, skills, career, business, finances. For each, determine whether it is passively stable (can survive without intervention, like a well-designed ship) or actively stable (requires constant energy input, like a fighter jet). Most people dangerously treat actively stable systems as passively stable. Your relationship, your health, your team culture, and your competitive position all require continuous energy input or they degrade toward entropy.Pro tipIf you have not actively maintained something in the last month, it is probably already degrading whether you notice it or notWarningPeople who confuse active and passive stability wake up one day to divorce papers, health crises, or organizational collapse that seemed to come from nowhere
- Budget Energy for Maintenance, Not Just GrowthAllocate explicit time and energy for maintaining what you already have, not just building new things. In business, this means regular staff training, inspection of processes, updating documentation, and ruthlessly eliminating bureaucratic sediment. In personal life, it means scheduling relationship maintenance, health checkups, skill practice, and home upkeep. Failing to pay this maintenance tax means entropy accumulates silently until a crisis forces emergency intervention at much higher cost.Pro tipCreate a recurring maintenance calendar that treats preservation activities as non-negotiable appointments rather than optional tasks
- Choose Your Battles Based on System EntropyApply energy where it will have the most impact by considering the existing entropy level of the system. The same 20 units of energy applied in a high-entropy system like a large bureaucracy will produce far less impact than the same energy applied in a low-entropy system like a small startup. This principle applies to competitive strategy: compete where your energy will be most efficient, and avoid wasting effort in highly entropic environments where most of your energy will be absorbed by the chaos.Pro tipIn a quiet coffee shop (low entropy), a cough is disruptive; in Times Square (high entropy), the same cough has zero impact. Choose your coffee shop.
- Maintain Focus as an Anti-Entropy StrategyThe number of projects and commitments you are involved in only seems to grow. Those who expend energy to maintain focus on one or two priorities get far more done than those who let things naturally expand. Focus itself requires energy -- it is an anti-entropy strategy. Without deliberate focus, your attention and resources spread thin across an ever-growing number of projects, with each receiving less and less effective energy until none produces meaningful results.Pro tipEvery time you add a commitment without removing one, you are increasing the entropy in your own system
Rudolf Clausius studied steam engines and observed that only a percentage of energy input was converted into useful work. The rest dissipated into the environment. He identified this natural tax as entropy and formulated the second law of thermodynamics: the entropy of the universe tends toward a maximum. This observation from 19th century physics became the foundation for understanding why all systems tend toward disorder.
Parrish describes imagining starting a company by putting 20 people in an office with an ambitious but ill-defined goal and no leadership, telling them they will be paid as long as they are there working. Two months later: five have quit, five are sleeping with each other, and the remaining ten have no idea how to solve the problems that have arisen. Nobody is closer to the goal.
Parrish uses the cough analogy: coughing in a quiet coffee shop (low entropy system) causes a big disruptive change, while the same cough in Times Square (high entropy system) has zero impact. The efficiency of energy expenditure is inversely proportional to the existing entropy in the system.
The concept of entropy was identified by German mathematician and physicist Rudolf Clausius between 1822-1888, who studied the conversion of heat into work and noticed that only a percentage of energy was converted into actual work. He solved this riddle by observing a steam engine and calculating that energy spread out and left the system, coining the term entropy intentionally to sound similar to energy. Shane Parrish popularized entropy as a mental model through Farnam Street, drawing on Clausius's original work, Arthur Eddington's 1927 concept of the Arrow of Time, and applications from Tom Stoppard, Brian Cox, Steven Pinker, and James Gleick to show how this physics concept applies to everyday decision-making.