Simplify the following text for a Grade 12 native English-speaking person.
Original: Sextus Empiricus ( c200 AD ) , the main authority for Greek skepticism , incorporated empiricism into the basis for asserting knowledge .
Simplified: Sextus Empiricus ( c. A.D. 200 ) , the main authority for Greek skepticism , developed the position further , incorporating aspects of empiricism into the basis for asserting knowledge .