CONCEPT
Tacit Knowledge
The vast, inarticulate substrate of understanding that operates beneath conscious awareness and cannot be captured in any specification, no matter how detailed—Polanyi's foundational insight that "we can know more than we can tell."
Tacit knowledge is Michael Polanyi's term for the dimension of understanding that resists articulation yet grounds all explicit knowledge. It is the diagnostician's sense that something is wrong before she can identify the symptom, the programmer's feel for a codebase about to break, the face-recognition capacity that operates instantly yet defies specification. This knowledge is not mystical or subjective—it is real, reliable, and built through years of embodied engagement with a domain. What makes it tacit is precisely that it operates subsidiarily, beneath the threshold of focal attention, supporting conscious judgment without becoming its object. The automation of explicit knowledge work by AI exposes tacit knowledge's foundational role: when machines produce outputs that meet every explicit standard yet lack the tacit ground that makes those standards meaningful, the distinction between competent performance and genuine understanding becomes acute.
In The You On AI Field Guide
Polanyi developed the concept across his career as a physical chemist before turning to philosophy.