Many systems are organized hierarchically. The CERNDOC documentation system is an example, as is the Unix file system, and the VMS/HELP system. A tree has the practical advantage of giving every node a unique name. However, it does not allow the system to model the real world. For example, in a hierarchical HELP system such as VMS/HELP, one often gets to a lead on a tree such as:
HELP COMPILER SOURCE_FORMAT PRAGMAS DEFAULTS
only to find a reference to another leaf: Please see
HELP COMPILER COMMAND OPTIONS DEFAULTS PRAGMAS
and it is necessary to leave the system and re-enter it. What was needed was a link from one node to another, because in this case the information was not naturally organized into a tree.
This, I think, is the brilliance of Notion, and what makes it one of the best examples of “fidelity to digital information” that I’ve come across. The structure of the app reflects the structure of the web itself: digital content is purposefully formatted, like semantic HTML elements, and exists in a hierarchical structure (directories on the web, nested pages in Notion), yet can be linked and referenced to create a complex network of information. And pages in Notion reveal the structure of the information: when nesting a page within a page, the child page always displays on the parent page. There’s no way to create a child page that doesn’t display on a parent page, no way to obscure the structure of the information. The semantic structure of Notion reflects the semantic structure of the web itself.
Truchet's approach was more topological than geometric, and the qualitative aspects of pattern take priority over the metric ones. His principles provide a kind of metaphor for the hierarchy of separation and connection in all things.
Ruskin's Seven Lamps of Architecture provided seven guides, or 'lamps', for the troubled craftsman, guides for anyone who works directly on material things. These seven are:
The lamp of sacrifice: The willingness to do something well for its own sake.
The lamp of truth: The truth that 'breaks and rents continually'; Ruskin's embrace of difficulty, resistance, and ambiguity.
The lamp of power: Tempered power, guided standards other than blind will.
The lamp of beauty: Which for Ruskin is found more in the detail, the ornament—hand-sized beauty—than in the large design.
The lamp of life: Life equating with struggle and energy, death with deadly perfection.
The lamp of memory: The guidance provided by the time before machinery ruled.
The lamp of obedience: Obedience to the example set by a master's practice rather than by his particular works; otherwise put, strive to be like Stradivari but do not seek to copy his particular violins.