A Taxonomy of Knowledge

It is a tool that humans developed to make the accumulated knowledge in a particular field useful by identifying hierarchies in the relationships among the members of groups.

Almost every systematic approach to learning begins with discussing taxonomy. For example, anyone who has taken a Biology class probably remembers starting with the Linnaean System for classifying living organisms into domain, kingdom, phylum, class, order, family, genus, and species. Similarly, digital information is named, described, and placed into hierarchical structures that can be navigated using user interface tools on websites. Medicine, mathematics, history, science, language—the teaching of virtually every subject at any level in school is arranged according to the taxonomy of that field.

Taxonomies themselves are not writ in stone. They are often revised as knowledge expands, reflecting new evidence and understanding. Knowledge itself can be arranged into hierarchical categories, but there is not one universal taxonomy of it. The structure differs depending on which field is describing and using it.

One very useful way to organize knowledge is arrange it into four categories: tactic, strategy, principle, and essence. A tactic is a specific technique that is used to solve a specific problem. A strategy is a way to group tactics together in order to understand when to use which techniques. A principle is the level of understanding the conditions and relationships that govern why tactics and strategies work in particular situations. Essence is the ultimate level of knowledge, identifying the foundational truth upon which the principles, strategies, and tactics function.

If we use cooking as an example, we might begin learning how to cook by picking up various tactics. These could be techniques like learning how to cut broccoli or brussels sprouts, how to season beef or chicken, or how much heat to use with olive oil or butter. Advancing to cooking strategies would involve learning recipes, which would guide us as to which technique to use to cut the ingredients, season them, and cook them, depending on the dish we are preparing.

 Advancing further, we might learn about the chemistry of cooking and the nutrient content of the various ingredients. Learning at the level of these cooking principles would deepen our understanding of why dishes are prepared a certain way. It would free us to explore new ways of combining the ingredients using various techniques (tactics) in order to develop novel recipes (strategies). Understanding cooking at the level of essence would mean studying the fundamental reasons why we cook at all: to prepare food that is healthy and appealing. This essential foundation, that cooking is a system of knowledge used to get the most nutrition and flavor out of food, explains and supports why we follow general principles, apply certain strategies, and employ specific tactics.

It helps to picture this taxonomy of knowledge as a tree. Seen in midsummer, the sheer number of leaves on any tree can be overwhelming and might appear random as the leaves orient themselves to sunlight, move in the breeze, and display different stages of growth in their life cycle. In this picture, the leaves are the tactics or techniques the tree uses to support and sustain its life. When we look at the twigs where the leaves are connected, we would see how their arrangement is not without order. The arrangement of the leaves follows the structure and shape of the twigs, just as tactics are clustered together through the organizing structure of strategies.

As clusters of leaves are arranged according to the structure and placement of the twigs, we observe how twigs are not dispersed haphazardly on the tree. They are distributed according to the structures of larger branches that are themselves arranged in patterns. In this way, strategies are not random phenomenon but expressions of underlying principles that govern their arrangement.

The essential nature of the tree emerges from the original seed as it breaks its shell and begins growing upward and downward, patterning the structure of the tree through the form of the trunk and main root. That essential foundation supports and guides the growth of branch, twig, and leaf.

More than just a useful metaphor, this taxonomy of knowledge points the way toward resolving the information overload surrounding mental health.