The Great Mental Models: Visual Book Summary
Volume 2 - Physics, Chemistry, and Biology
Some quick context before we get started ↓
I recently shared this post exclusively with paid subscribers, but after a restructure of my paid plan I’m sharing it for free.
This is my biggest project to date. It took around three months to create all the illustrations from scratch and I’m excited to now be sharing it with everyone.
If you missed my last post, all paid subscribers will be receiving a free physical copy of Derek Sivers’ latest book as well as access to my upcoming visual vault as a ‘thank you’ for all the support. Deadline to sign up for this is Sunday.
The book alone costs more than double the subscription fee, so it’s a no-brainer.
The Great Mental Models:
This is an illustrated summary of the second book in Shane Parrish’s ‘The Great Mental Models’ series, including 20 brand new illustrated ideas — my most ambitious project to date.
The series contains four books:
Volume 1 — General Thinking Concepts
Volume 2 — Physics, Chemistry, and Biology
Volume 3 — Systems and Mathematics
Volume 4 — Economics and Art
I’ll be creating a visual summary for each one, with the first volume already posted.
Contents:
Theory of Relativity
Reciprocity
Entropy
Inertia
Friction & Viscosity
Velocity
Leverage
Activation Energy
Catalysts
Alloying
Natural Selection
Adaptation Rate
Ecosystem
Niche
Self Preservation
Replication
Co-operation
Hierarchical Organisation
Incentives
Energy Minimisation
Theory of Relativity:
Perspective influences what we perceive as reality.
Both Galileo and Einstein demonstrated that observers in relative motion or different positions experience events differently, yet both can be simultaneously correct.
It is important to recognise your own imperfect and limited perspective and actively seek out multiple viewpoints to gain a more complete understanding of any situation, especially when stakes are high.
By imagining how others see the world, you can identify blind spots and design more effective solutions.
Reciprocity:
When you act on things, they act on you.
Inspired by Newton’s third law, this model advises adopting a "win-win" approach in relationships and interactions.
By ‘going positive and going first’ you are more likely to receive positive actions in return, as life is an iterative and compounding game.
Whether in physics or human behaviour, every force or action has a reciprocal effect, making it a better strategy to engage in positive behaviour for long-term mutual benefit.
Entropy:
Disorder is the natural state of equilibrium.
Change and decay are inevitable. Anticipate things falling apart and focus on prevention.
→ Rooms get messy unless we tidy them
→ Societies become unlawful unless we police them
It requires constant effort to prevent disorder and maintain complex systems.
Narratives and shared understandings are human attempts to impose order on chaos.
Inertia:
Starting a new habit is hard, but so is stopping an old one.
Objects (and ideas or habits) resist changes to their state of motion unless acted upon by an unbalanced force. The "mass" of a habit or idea (i.e. how long it has been around) increases the force required to change it.
To overcome resistance to change, you must recognise this inherent difficulty and apply sufficient, sustained force.
Friction & Viscosity:
What is easy in one environment can be hard in another.
Friction and viscosity are forces that oppose movement and impede progress.
Friction affects objects in contact
Viscosity measures a fluid's resistance
It's often easier to reduce resistance than to apply more force.
By shaping your environment to minimise opposing forces (whether physical obstacles or mental barriers) you can reach your goals more easily.
Velocity:
If you get on the wrong train, get off at the nearest station. The longer it takes you to get off, the more expensive the return trip will be.
Speed is how fast you go
Velocity is how fast you go in a specific direction
Constant speed in the wrong direction is counter-productive. It is more important to pay attention to where you are going than how quickly you will get there.
Leverage:
Look out for asymmetrical opportunities.
An asymmetrical opportunity is one in which the output is greater than the input, usually created due to an ‘unfair advantage’ that one party has over another.
To wield leverage effectively, you must understand:
→ What is the potential
→ When and where to apply it
→ How to keep it
The best leverage often comes from not needing a particular deal and applying pressure thoughtfully to create win-win scenarios, as excessive force can backfire.
Activation Energy:
Don't underestimate the effort needed to effect lasting change.
Activation energy is the initial input of energy required to start a reaction and power it through to a sustainable conclusion.
Revolutions often fail by focusing only on breaking the old structure and not on building the new.
Plan for enough ‘kindling and flames’ to sustain the desired change.
Catalysts:
There is often a side or back door to speed up success.
Catalysts accelerate change by creating alternative pathways for reactions to occur, significantly reducing the time and energy required, but they cannot make a reaction happen that wouldn't otherwise.
You can spend all day trying to guess the code to a lock, but it’d be much quicker and easier if you just had the key instead.
Catalysts are not consumed and can be reused, making them highly efficient.
Identify and use the right catalysts to make things easier and faster, while recognising they are value-neutral and can speed up negative changes too.
Alloying:
Things are not always equal to the sum of their parts.
Alloying is the process of combining different components to create a substance with unique and greater strength or improved properties than its individual elements.
Combine a canvas, a brush, and some ink and you may have a valuable piece of art.
Seek combinations where one plus one equals ten.
Natural Selection:
Don’t put all your eggs in one basket.
Natural selection is a process of ‘non-random elimination’ where traits useful now are favoured over those which may or may not be useful sometime in the future.
Organisms (or traits) must be resistant to changes in their environment.
The best way to build resilience is to diversify.
Adaptation Rate:
You are a mouse and the world is a cat.
When things change, you must be willing and able to adapt to these changes — and you should be aware enough to be able to do so quickly.
Imagine you are a chameleon trying to evade predators. Your goal is to go totally unseen. If the summer leaf that you use as shelter suddenly turns orange in autumn, you’ll stick out like a sore thumb if you don’t also change yourself.
Be ready and willing to let go of what worked in the past to thrive in the future.
Ecosystem:
Nothing exists in isolation.
An ecosystem is an interconnected web of interacting species and their environment.
Understand these complex interdependencies and respect the system's ability to self-organise into a stable (but chaotic) equilibrium.
Uninformed interventions often do more harm than good.
Niche:
Different species’ have different roles in an ecosystem.
Generalists have broad needs and face more competition
Specialists have distinct needs and face less competition
Specialists thrive in stable environments but face extinction with rapid change, while generalists endure constant competition but have greater flexibility.
Understand whether you (or your product / company) are a generalist or a specialist and strategise accordingly.
Self-Preservation:
Humans are animals with innate survival instincts that kick in when under pressure.
Fight — Stand your ground
Flight — Run away
Freeze — Do nothing
While immediate self-preservation can protect us from danger, long-term survival often requires overriding primal instincts for greater collective or future benefit.
Recognising these behaviours in others can also be a useful social tool.
Replication:
Exact copies perpetuate the good, but they also perpetuate the bad.
Replication of living things is imperfect and doesn’t create exact copies. Errors inject diversity, both good and bad, creating something new and facilitating adaptation.
Replication, in reality, is more like iteration.
Co-operation:
In game theory, a win-win scenario is referred to as ‘positive-sum’.
Cooperation, or symbiosis, occurs when organisms fill each other's needs, creating positive-sum relationships that yield emergent properties greater than the individual components.
Seek out opportunities for collaboration and mutual benefit.
Hierarchical Organisation:
Hierarchies are a natural and often necessary form of social structuring that provide order and direction, particularly in times of crisis.
While they can stifle creativity and create inequality, eliminating them entirely often leads to unspoken, more disordered structures.
Recognise that hierarchy is inevitable and aim for purpose-driven structure.
Emphasise group belonging over individual status and prioritise leaders who actually serve the needs of the group, rather than just being the most dominant.
Incentives:
Human behaviour is shaped, often irrationally, by incentives driving us towards reward and away from punishment.
Humans have a bias towards short-term gain over long-term gain, which can sometimes lead to poor decision-making.
Always consider the real incentives at play, understand their manipulative power, and try to align them with your long-term values.
Use incentives to encourage positive change in yourself and others.
Energy Minimisation:
All living beings, including humans, have an innate tendency to conserve energy.
Our brains use ‘heuristics’ (mental shortcuts) to make quick and efficient decisions, saving cognitive load but often leading to biased or suboptimal results.
Recognise this natural laziness and consciously expend extra energy when you know you might need it (e.g. for a large irreversible purchase like a house or a car).
Design frictionless environments that make good habits easy so you have less of an incentive to not do the thing you want to do.
I hope you liked this illustrated book summary.
I’ll be sharing more soon with a few others already fully complete and ready to send.
It took a lot of work to make this happen and I’m excited to share more with you.
Remember to upgrade your subscription before Sunday to get a free physical copy of Derek Sivers’ latest book sent to your door.
If you enjoyed this, let me know which mental model was your favourite and feel free to share it with a friend, colleague, or your followers. It’s totally free for everyone and shares go a long way. Thanks.
I appreciate the effort you put into it, Lewis! :)
“It is more important to determine
where you are going than how quickly you will get there.”
Illustrations and concepts very well done.