Wikipedia is not a reliable source definitely in the case that its articles can't reference its other articles, but also now generally in the academic world. British Broadcasting Corporation (BBC) mentioned a study describing Wikipedia tends to be equally as accurate as, or more accurate than, top encylopaedias... but Wikipedia also has articles altered by vandalism/blanking, people pushing non-neutral viewpoints (or being deluded they are neutral, or some version of ‘neutral’ seen more out-of-date) and a large degree of conformity/groupthink/bureaucracy, and an overall Wikipedia viewpoint, because of editor majority demographics, administrators' popular sociopolitics, deletionism/etc. (and on the other hand, creation of too many irrelevant popular culture articles, often named historical terms until fixed, changed back, explained, fixed), scandals & the cabal, and because 2/3 to 95% of humans are irrational, mostly sophists (many trolls). Wikipedia used to seem helpful for writing various papers but now has been seen as a poor (usually banned) source for any level academic papers on subjects such as humanities & social science, and probably all science (though may be okay place to find sources cited, and check, but not as good a library, best with a professional reference librarian of higher academic degree).
     The wiki concept & Mediawiki software seem to be Wikipedia's best things, rather than some of the material, which you may find better elsewhere like other literature including books and from experts/schools, special topic wikis.

Below, related ones I didn't create are in parentheses, and I didn't create ones describing sections.

society/culture/arts

• American Vegan Society
• Athenic: 'of Athens or Athena' (now redirected)
• Delphic maxims (some ancient Greek sayings)
• Darwin (given name) (English redirect to Anglo-Saxon, now has article)
• some Hermetic definitions
• Howard David Johnson (modern realist artist)
• Lucifera
• Wikiversity: a standard art exercise. four Comparative Religion classes... (now I'd say most religions are cults but haven't had time to change that, or ignavi would probably revert it).

technical arts/sciences

• orthopathy (Nature Cure, Natural Hygiene. When editing use WP:MEDRS policy)

liberal arts/science

general education

history & modernity

• of philosophy: Greek: Scholarch (head of any ancient/Classical Greek school)

trivium

grammar

• some now deleted definitions in ‘hacker’
• other definitions of jivan/para mukta (Wiktionary:paramukta), Wiktionary:philalethia

quadrivium

arithmetic

• Wikibooks:Arithmetic ... Multiplication: fundamental theorem of arithmetic

geometry

• Wikibooks: Geometry Ch. 11: Realspace
• coordinate systems: Synergetics coordinates (redirected. See also Cartesian)
• vici: विची (Sanskrit), wave (in mathematics, water, etc.)

interdiscipline

science & engineering

mathematics: algorithmics & computer science

• trusted computer system (now redirected)

mathematics: calculus/mathematical analysis

• applied analysis (in engineering analysis)

philosophy

• mathematicism

userboxes

• Central Washington University userbox
• no singular 'they'

philosophy/sacred arts/sciences

general

• philalethia (redirect)

(meta)physics (nonsense except mathematics)

arithmology

• Wikibooks: Grammar, Arithmology, And Isopsephy (gave up on and most ‘New Age’)

biography

• Cedercrans, Lucille

• Powell, Arthur E

• Pryse, JM

ontology

• causeless cause

• form(lessnesse)s: arupa (see also rupa, ideal forms)

• hyperplanes (worked on but didn't create all... mostly redirected): adi/divine/logoic plane, anupapaduka/monadic plane, spiritual plane, buddhic/causal plane, (higher) mental plane, astral plane, ethereal plane, plane (metaphysics)

• self: antahkarana

• mathematicism

• noeta (now disambiguation)

cosmology

• energies: Shaktis (Shekhinahs): Iccha, (see also Devis Prakriti, Jnana, Kundalini, Kriya, Mantrika, Para... redirected most these were articles)

userboxes

• Pythagoreanism
• Platonism
• Neopythagoreanism
• Neoplatonism
• Leibnizianism
• mathematicism
• WikiProject Yoga

• discouraged (Lucifer image)

• mathematics: synergetics coordinates
• musicians/techno/trance: Jeremy van Kampen (Laughing Buddha of Cosmosis)
• philosophy/metaphysics/spirituality: Chakrology (2, 3, notes), Theism
• my userspace

occultist Bosivio, Santiago; actress, Jefferson, Paris; Hellenismos portal (Hellenismos culture/philosophy/religion), mental projection, triple manifestation