For some reason, I could never get Richard Zach’s Ptolemaic Astronomy diagrams to work correctly, so I set out to write my own macros for TikZ that would allow me to draw Lewis system of sphere diagrams like these.

If you’re like me, you like representing philosophical ideas with intersecting circles. Here’s how to draw them in TikZ.

Here, I’ll walk through how to code causal modeling diagrams in TikZ, like the following: