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.
How do we know what’s the right direction [for computers to take]?
Ultimately it comes down to taste. It comes down to trying to expose yourself to the best things that humans have done, and then trying to bring those things in to what you’re doing.
Picasso had a saying: “Good artists copy, great artists steal.” And we (at Apple) have always been shameless about stealing great ideas. And I think part of what made Macintosh great was that the people working on it were musicians and poets and artists and zoologists and historians who also happened to have been the best computer scientists in the world. But if it hasn’t been for computer science, these people would all be doing amazing things in life in other fields. And they brought with them — we all brought to this effort — a very liberal arts air, a very liberal arts attitude, that we wanted to pull in the best we saw in these other fields into ours.