Spread across the Disc live many philosophers, great (and arguably, less great) thinkers who solve the mysteries of the universe. The most fertile philosophy-ground seems to be around the Circle Sea, in places like Ephebe, but the Counterweight Continent also contends. Uberwaldean philosophers of the Bonk School are referenced by Nutt in Unseen Academicals.
Philosphers in Ephebe tend to be of the beardy, bald type often wearing little more than a towel. Sometimes a little less too, but no philosopher would let the state of their dressedness interfere with a good idea. Philosophy includes logics, theology, social-economics, mathematics, and "natural philosophy" (physics, etc).
It is mentioned in The Light Fantastic that sometimes a troll will go into the hills, sit down, slow down, and catch philosophy as if it were a disease. It may very well be a disease to trolls, as a troll who has been philosophizing like this for long enough will eventually lose all sentience and just become an ordinary rock. The only known example of a troll catching philosophy in this manner is Old Grandad.
- Scoplett, a sailor who thinks too deeply for his own good.
- Wen the Eternally Surprised (from the High Hublands)
- Ventre (from Quirm)
- Sceptum, medical ethicist who laid down an operating framework for medical doctors