Full Idea
Pherecydes of Syros said that the principle and element of all things is earth.
Gist of Idea
Pherecydes said the first principle and element is earth
Source
report of Pherecydes (fragments/reports [c.600 BCE]) by Sextus Empiricus - Against the Physicists (two books) I.360
Book Reference
Sextus Empiricus: 'Against the Physicists/Against the Ethicists', ed/tr. Bury,R.G. [Harvard Loeb 1997], p.173
A Reaction
Sextus is giving the history, and mentions it before saying that Thales thought it was water. Earth seems a sensible starting point, and I am guessing that Thales was trying to think a bit more deeply than Pherecydes about it.