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Learning Thinking Creating

I'm interested in the biological and cultural evolution of humanity, the problems we face today, and how we can thrive on both an individual and collective level. From this perspective, I try to develop integral solutions driven by social entrepreneurship.

Lennart van Tuijl

About

Hi, I'm Lennart. Welcome to my corner of the internet.

I've always been curious about more subjects than fit in one job title. It started with the natural sciences and technology: how things work, and why. Over time the humanities and the social sciences pulled me in just as hard, because they ask the same question about a much messier subject: us. At some point the subjects stopped feeling like a collection and started feeling like one question. What are we, how did we get here, and what do we do with that?

Three words sum up what I do with that question.

  • Learning

    I read and research across whatever field has something to say about us: evolutionary biology and neuroscience on how we're built, psychology on how we behave, history and economics on how we organize ourselves, and technology and AI on where all of that is going. The questions I keep coming back to: why sleep, food, and attention are so hard to get right in a world of plenty, how cultures evolve, and what AI is doing to the way we think.

  • Thinking

    Mostly connecting the dots between those fields, and being skeptical of my own first conclusions. I think in systems: feedback loops, incentives, delays. The same loop that keeps your body temperature steady explains why habits stick, why a broken streak feels like a verdict when it's only a measurement, and why institutions drift. Writing is how I do this thinking in the open. Putting it online means someone will tell me where I'm wrong, which is still the fastest way to find out.

  • Creating

    Turning what I learn into things that are actually useful, starting with myself. LifeCore is the clearest example: a system for self-improvement I'm building because every app I tried solved only part of the problem. I build with AI tools, which means I'm not a developer in the traditional sense, and I'd rather say that out loud than hide it. What matters is that a thing works, and that it's as complete as I can make it within its own corner.

If you're wondering where this way of looking at things comes from: Carl Sagan and Isaac Asimov, mostly, and the handful of writers who treat one big question as a reason to learn every field it touches.

If you'd like to share something or ask a question, feel free to get in touch.

Writing

Thinking out loud.

Sapiensphere is where I write about one question: what are we, how did we get here, and where are we going? That question doesn't fit in one field, so the essays don't either. They start close to home, with the body and the brain, and work outward: other people and the cultures we build, the planet we depend on, and now and then the much larger picture we're a small part of.

Every piece tries to do three things: explain how something works, connect fields that don't usually talk to each other, and end with something you can use. Long reads rather than hot takes.

Projects

What I've created.

These are the projects I've finished or am working on.

LifeCore logo

LifeCore

A self-improvement system I'm building

building

One place for the whole loop of getting better at something: life areas, goals, habits, the day itself, and looking back on it. I'm building it out of necessity: most apps solve one piece, and the ones that try to do it all never quite work the way I want.

Self-improvementHabitsGoals
In progressNot public yet

Contact

Say hello,
I'm easy to reach.

If you have anything to ask or share, don't hesitate to send me a message. You can email me, or reach me through one of my socials. I try to reply as quickly as I can.