A very educated person told me that in order to understand other philosophers I need to start with Pythagoras. I searched on the web for books written by Pythagoras, but without success. I understand that Pythagoras lived during the 6th century BCE - did any of his books survive?
NONE. No books (if any) or fragments from Pythagoras are extant.
You can read at least :
- Walter Burkert, Lore and Science in Ancient Pythagoreanism (1st German edn.,1962).
We have only some fragments from the teachings of Pythagoras, no complete work. In particular, there do not exists six books written by Pythagoras which have survived.
Pythagoras was the founder of a school, which ranked numbers and elementary mathematics and possibly also some form of esoterics very high. A lot of sayings is attributed to Pythagoras by his pupils. But we do not know what he himself really said nor the exact meaning of many of his sayings.
One saying ascribed to Pythagoras reads:
The whole heaven is harmony and number.
One can read off from this statement the belief that the world does not exist primarily due to its material basis - e.g., water according to Thales - but due to an intellectual principle. According to this interpretation the statement is similar to todays view, that the fundamental laws of nature must be stated in a mathematical language.