How do you balance on a bike? We say "like riding a bike" to describe the things we never forget, but none of us can explain how we learned it in the first place. This is tacit knowledge: "we know more than we can tell."1
But a robot can learn to balance on a bicycle. So is tacit knowledge really a human advantage?
What I love about this question is that the bicycle is a machine. Balance isn't knowledge instead of a machine - it's knowledge of one, inseparable from it. Humans are tool builders (Jobs called the computer "a bicycle for the mind"2) and our oldest advantage has never been judgment apart from our tools; it is judgment fused with them.
You can hear a version of this argument making the rounds: as artificial intelligence commoditizes explicit knowledge, tacit human judgment becomes the durable edge.3 We mostly agree. The nuance is where that judgment lives.
Although my daughter wouldn't describe it this way, learning to ride a bike is a kind learning environment: feedback is honest, immediate, and repeatable.4 Conversely, Markets are wicked: feedback arrives late and noisy. Intuition compounds in kind environments; in wicked ones, experience breeds confidence faster than skill5—and we judge the machine's mistakes far more harshly than we've ever judged our own. Whatever the tacit edge is, it was never our feel for markets.
It was always our feel for people. The sociologist Harry Collins split tacit knowledge in two: somatic, the body's skills like balance, which machines can master; and collective, the kind that lives between people.6 In our non-ergodic world the client lives a single path7—some falls are a scraped knee; others are ruin. So the focus is stewardship: keeping a particular family balanced. And clients, like the rest of us, know more than they can tell about what their wealth is for—it must be drawn out over years, tacit to tacit. Portfolios can follow manuals. Clients require journals.
That is why we at SS&C ALPS Advisors build the technology we do. The explicit layer—rebalancing, tax management, reporting—is where the machine is better, and refusing to cede it borders on malpractice, especially once everyone holds the same manual. Our role is the mechanic's: maintain the machine so the rider always has something reliable to ride.
Balance is a constant stream of small corrections. Peace of mind, as Pirsig said, is "the whole thing": good maintenance is whatever produces it.8 An adjustment doesn't need to be optimal—it is good if it keeps the rider upright. Balance is not a state you reach; it is a practice you perform the whole way home. So is trust. So is peace of mind.
Important Disclosures & Definitions
1 Polanyi, M. (1966). The Tacit Dimension.
2 Krainin, J. & Lawrence, M.R. (1990). Memory & Imagination: New Pathways to the Library of Congress. Krainin Productions. Steve Job's “Bicycle for the Mind” metaphor draws on a Scientific American study ranking a human on a bicycle the most efficient form of locomotion on earth.
3 Tung, T. & Roussiere, P. (2026, March 16). Tacit Knowledge Is Your Next Competitive Moat. California Management Review.
4 Hogarth, R. (2011). Educating Intuition. Epstein, D. (2019) Range: Why Generalists Triumph in a Specialized World. Hogarth and Epstein explore the distinction between kind and wicked learning environments.
5 Kahneman, D. & Klein, G. (2007). Conditions for Intuitive Expertise: A Failure to Disagree. American Psychologist 64, no. 6.
6 Collins, H. (2007). Bicycling on the Moon: Collective Tacit Knowledge and Somatic-limit Tacit Knowledge. Organization Studies 28, no. 2.
7 Peters, O. (2019). The Ergodicity Problem in Economics. Nature Physics 15.
8 Pirsig, R.M. (1974). Zen and the Art of Motorcycle Maintenance.
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