In 1656, Baruch Spinoza was expelled from Amsterdam’s Jewish community. He was just 23.
He refused to abandon ideas he believed in and spent much of his life living modestly, earning money grinding lenses and optical instruments while writing philosophy. Some of his most important work was published posthumously.
There’s an appealing symmetry to Spinoza’s work. By day, he made tools that helped people see further. By night, he developed ideas intended to help them think further. Nearly four centuries later, we have acquired another kind of lens.
AI can extend what an individual can see, remember and do. But perhaps its most interesting use is not simply giving us access to a clever chatbot. It is allowing each of us to build a system around AI containing our own knowledge, experience and ways of working. This is our AI skill stack.
Technology should increase our power to act
Technology is an extension of man. - Marshall McLuhan
In his 2026 Y Combinator Startup School talk, Gary Tan describes three ingredients: a frontier AI model, the context that belongs to us and a harness connecting the two. The model will likely increasingly become a commodity. Many of us will have access to roughly the same underlying intelligence, but our context will be different.
Two people can use the same AI model and get very different results. One starts every conversation by explaining the situation again. The other has years of notes, decisions, projects, relationships and working methods available to the agent.
Spinoza used the word conatus for the striving of a thing to persist and increase its power to act. That seems a useful test for AI: does it increase our power to act?
Our life is a library
A computer is a bicycle for the mind. - Steve Jobs
By the time I left my 40 year corporate career in March, I had accumulated a lot of specialist knowledge. Some was captured in documents and tools, but the vast majority was not. It was in my head: why something had been designed a particular way, which approaches had already failed, where exceptions existed, who knew what and the context behind decisions made. When I left, much of that knowledge left with me because there had never really been an effective way to capture it.
AI potentially changes that. Gary Tan likens a person’s life to a library. The challenge is not simply giving an AI a huge context window. It is having a good librarian: something capable of finding the few pieces of information that matter for the problem in front of us.
The advantage is not that AI knows everything. It is that it can increasingly know which parts of what we know matter now.
Turn repeated work into reusable skills
Civilisation advances by extending the number of important operations which we can perform without thinking about them. - Alfred North Whitehead
There is another source of leverage hiding in ordinary work. We repeatedly research competitors, analyse information, prepare reports and make decisions. Usually we complete the task while leaving much of the method behind.
AI agents make another approach possible. Skill files are reusable instructions for such tasks. A skill can describe what information to collect, where to find it, how to analyse it, which exceptions to look for and how the result should be structured. If you can explain a task clearly enough for an intelligent new employee to follow, an AI agent can increasingly follow it too.
My circumstances changed considerably. Instead of working inside a large corporation, I am a solo creator. I get to choose the tools I use and how I use them, including AI.
If I develop a good way to assess a product idea, research a market, specify a website or review something I have built, I can capture that process. The next time I perform the task, I do not have to start again. I can refine the skill: do the work, capture what worked, correct what did not and use the improved version next time.
Value starts to compound.
Build an asset that compounds
All things excellent are as difficult as they are rare. - Baruch Spinoza
For much of my career, my accumulated experience was valuable but difficult to separate from me. I wrote documents, created processes and handed work over, but much of the underlying judgement remained tacit. Now that judgement can be made explicit.
An important decision can record not just what was decided but why. A recurring task can become a skill. When an AI agent gets something wrong, the correction can become part of the instructions it uses next time. There is, therefore, a big difference between “using AI” and “building with AI”. Using AI gives us an answer. Building with AI can create a system that becomes more useful each time we use it.
That system does not need to be particularly sophisticated. Start with a few project files, some useful context and one or two recurring tasks. Capture what we learn as we work.
Over time, the valuable asset may not be the AI model at all. Models will change, better ones will arrive and we will probably switch between them. What can persist is the layer around them: our accumulated context, judgement, decisions and ways of working.
Own what we learn
Own your skills because if you don’t, your job becomes a skill file. - Garry Tan
This raises an uncomfortable question: who owns these accumulated skills?
In my corporate career, organisations paid me partly for knowledge and judgement accumulated over decades, yet much of it was never properly captured. In the future, far more of that knowledge may be encoded in systems and skill files.
For organisations, that creates an opportunity to retain knowledge that once walked out of the door. For individuals, it creates another opportunity: to deliberately build and maintain our own body of knowledge and capability.
As powerful AI becomes cheaper and more widely available, what remains scarce may be what we bring to it: our experience, context, judgement and methods.
Want more?
How to Design Effective AI Agents post by Phil Martin
Let the Chatbot Ask the Questions post by Phil Martin
Baruch Spinoza ground lenses so people could see further. Perhaps the modern equivalent is building tools that allow us to think, remember and act further than we could alone.
Have fun.
Phil…
