via Pascale
1. MDMA
2. Entactogen
3. Psychoactive drug
4. Chemical substance
5. Chemistry
6. Science
7. Knowledge
8. Description
9. Rhetorical modes
10. Exposition (which goes to Expository writing)
11. Writing
12. Language
13. Human
14. Living
15. Biology
16. Natural science
17. Naturalistic (goes to Naturalism (philosophy))
18. Philosophical (goes to Philosophy)
Now that I've seen a few examples I can see how it works, crazy as it is. Most entries tend to start with a high level categorical links. Which pretty quickly sends you up into the "ideas plane" which of course ends up in philosophy.
Fewer steps: MDMA, Psychotherapy, Existentialism, Philosophy. Boom goes the dynamite
Bah, I can't read the rules. Nevermind.