Thoughts About the Second Brain
21 May, 2025
If you’ve been hanging around, or just skirting the fringes of, personal productivity and personal knowledge management circles, you’ve probably come across the term second brain.
At it’s most basic, a second brain is a tool that acts like a super charged, digital filing cabinet. One in which we store and classify and organize information from diverse sources — all in one place. A second brain is seen in some circles as an antidote or panacea for dealing with the volumes of information many of us take in.
Applications that purport to act like a second brain become a dumping ground for ideas. For thoughts. For notes. For bookmarks. For tasks. And even if you carefully organize your content, a tool can quickly become like that certain closet or drawer in your home — a place where a lot of cruft piles up.
Second brain tools enable us to store the information that we need or that we think we might need. In doing that, we wind up with more than we actually do need, but which we can’t bear to get rid of because we’ve embraced a contingency mindset around the information in a tool.
I also see the idea behind the second brain to be based, at least partially, on a limited view of what the human brain actually does. Of what the human brain is actually capable of. Our brains aren’t merely storage media. They’re not only receptacles for facts and information.
Second brain applications don’t do heavy lifting for you. Our actual brains do that.
Our brains are powerful connection machines capable of forging links between disparate bits of information floating around in our memories. Our brains connect thoughts and ideas, often without us realizing that’s happening. Our brains bring information and facts together, crystallizing it in the form of knowledge. Our brains can spark those wonderful eureka moments, those realizations that we’ve cracked a problem or are on the right path to doing that.
All of that’s done not simply because we poked information into our brains but because our brains performed acts of parallel processing. Parallel processing that might have been helped along by using physical techniques like mind mapping or brainstorming or freewriting or using a method like Oblique Strategies.
No matter how good a tool is, it doesn’t do what our brains do: process that information, assimilate it, make sense of it. Our brains find common ground between our tacit knowledge, acquired through experience and learning, and the information we’ve added to the mix by reading and writing and viewing. Tools don’t bring imagination and logical facilities to bear on a problem. Let’s be honest: no application can really do that.
Those second brain applications that many people embrace and tout do have their uses, though. More as repositories than processing hubs. More as reminders of information that we’ve accumulated, reminders and information that can help spark the processes our physical brains use to turn information into knowledge.
Second brain tools don’t guarantee that you’ll remember something. If you’re like a lot of people, what you put into those applications gets buried under several strata of facts and information. Stuffing notes and ideas away like a squirrel hoards nuts isn’t going to do you any good. You’ll just increase your digital clutter. You’ll just add to your cognitive overhead.