Russel Ackoff's statement that this particular model, Beauty, Good, Truth, Economy, is necessary and sufficient for any social system. wiki 
Marc observed that the order of these elements has an impact. Eric enumerates the choices. observable
I've found value traversing the edges of Marc's community action tetrahedron while transcribing elements of a property graph. wiki
//wiki.ralfbarkow.ch/assets/viewstl/viewstl.html?stl=https://wiki.ralfbarkow.ch/assets/pages/marcs-tetrahedron/ellipsoid.stl HEIGHT 370
I started my design with lettered balls. These were tricky enough to place and orient. Correctly connecting them with sticks was not a simple extension. So I joined the nodes with a larger ball and punched viewing holes in this opposite each letter. A little squashing of the first elements put all of the parts in proportion.
module ball(letter) { translate([0,0,20]) { scale([1,1,.45]) sphere(d=20); scale([1,1,1]) translate([-4,-5,-5]) linear_extrude(height=10.5) text(letter); } }
I made the object hollow with gaping holes so that one could see all of the letters at once. I've painted the outward facing letters white. I find handling it continuously exposes new letters. The effect shares something with our guided node creation. Each turn seems to ask, have you thought about this? Try slow playback.
This shape needs a name. I will call it the Linkon, a homophone of Russell Ackoff's middle name. In the verb form "linkon" is pronounced "link on", as one might exhort another to create new wiki pages.
pages/marcs-tetrahedron
Revise this model online to use your own preferred letters. Click edit to start editing. Find "BGTE" in the model. Replace that with four letters of your own. Click out.stl to download the revised file for printing. edit
How OpenSCAD became available on the web. post