Why is documenting know-how an essential act of transmission?

Human history is not merely made up of monuments and laws; it is woven from skills passed down through generations. Every skill begins with a gesture—one that is repeated, refined, and transmitted without a second thought. These gestures, this so-called "tacit" knowledge, are nonetheless fragile. They often rely on the bodily memory and experience of those who possess them. When they pass away, this invisible heritage, this "knowledge in action," gradually fades away.

One example of this fragility is that of Roman cement ( Opus caementicium ). Ancient structures, such as the Pantheon or seaports, demonstrate exceptional durability, often surpassing the performance of our modern concretes.

Today, scientific analysis reveals a profound truth: while the ingredients were explicit (lime, volcanic ash), the mastery of the process was tacit. Documenting this know-how is therefore not a mere formality: it is an imperative for cultural and epistemological preservation, essential for life and crafts.

1. Lessons from Antiquity: The Proof of Technical Forgetting

The case of Roman cement is a casus belli for documentation, because it proves that knowledge of the "what" is not enough.

A. Tacit Knowledge: The Heart of Roman Genius

Studies (Jackson et al., 2017) have identified the key to this durability: the formation of hydrated calcium aluminosilicate (CASH) crystals, which give the material exceptional stability. These crystals form primarily through the low-temperature firing of lime and the use of volcanic ash (pozzolana).

But it wasn't the recipe that was lost during the decline of the Empire, it was the mason's tacit knowledge:

• Empirical Judgment: The exact firing temperature of the lime, the mixing time, and the management of drying conditions (hot mixing) were subject to the worker's sensory judgment. This judgment, this "unspoken knowledge," was never recorded.
  
  
• The Implication: When the master masons departed, this mastery of critical variables fell into oblivion for centuries. The knowledge resided in the hand and eye of the expert, not in a text .

B. The Theoretical Foundation: The Iceberg of Knowledge

This enigma perfectly illustrates Michael Polanyi's theory (1966): "We know more than we can say." This tacit knowledge is the invisible part of the knowledge iceberg. Documentation is the crucial step in externalization (Nonaka & Takeuchi, 1995), transforming an individual's experience into a shareable resource.

2. The Documented Gesture: An Act of Preventive Archaeology

Documenting know-how means adopting a historical and anthropological perspective for the future.

A. Capturing Real Work

The documentation must go beyond the ideal description of the process. It must capture the actual work – the human intelligence deployed by the craftsman to adapt to variability (material defects, changes in humidity, etc.).

• The Sensory Challenge: It is necessary to record the narrative of the adaptation process and the sensory cues (the sound of the tool, the texture of the material, the setting time) which are impossible to describe on paper. Success lies in these margins of maneuver that the expert manages through intuition and experience.
  
  
• The Role of Art: The approach aligns with the intentions of master artists like Leonardo da Vinci, who sought to dissect the anatomy and kinetics of gesture in order to grasp its profound essence.

B. The Seal for the Future

The lack of documentation on past techniques (such as Roman cement) has forced Experimental Archaeology today into decades of trial and error.

• The Lesson of History: By documenting the skills of a carpenter or art restorer today, we produce a comprehensive primary source that will not need to be reconstructed hypothetically a century from now. We are doing pre-archaeology, ensuring the complete traceability of the history of these trades.

3. Transmission: An Act of Cultural Safeguarding

The ultimate challenge of documentation is societal: it is about preserving the diversity of work cultures.

A. The Dignity of Intangible Heritage

Know-how is not simply a skill; it is a pillar of cultural identity. The UNESCO Convention for the Safeguarding of the Intangible Cultural Heritage (ICH) (2003) explicitly protects "know-how related to traditional crafts" .

• The Status of the Gesture: The act of documenting is the first step towards the inventory and official safeguarding of this intangible cultural heritage. It confers upon the gesture a cultural dignity, far beyond its utilitarian function, and ensures the continuity of craft lineages.

B. Lineage and Recognition

Highlighting expertise is a public recognition of an individual's skill. The act of transmission values ​​the master craftsman and legitimizes a person's working life. It creates a tangible link between generations, allowing the apprentice to feel connected to a long historical lineage rather than simply to a contemporary task.

In conclusion, documenting know-how is choosing heritage. It is transforming individual and ephemeral gestures into explicit and lasting technical heritage, ensuring that today's arts and crafts will not become tomorrow's archaeological enigmas.

The impact of documentation is also societal, as know-how is a pillar of culture.

• The UNESCO Convention for the Safeguarding of the Intangible Cultural Heritage (ICH) (2003) explicitly protects "know-how related to traditional crafts" . The act of documenting is the first step towards the inventory and official safeguarding of this ICH.
  
  
• Recognition: Highlighting expertise is a public acknowledgment of that expertise, legitimizing the expert as a bearer of technical tradition. This strengthens commitment and facilitates intergenerational transmission.

Conclusion

Documentation is not a mere administrative task. It is an act of knowledge engineering which, drawing on history and science, ensures that the technical ingenuity of our time will not suffer the same fate as the secret of Roman cement. We transform individual and fragile actions into an explicit and lasting technical heritage.