Buddha:

Indian philosopher of 5th- 4th century BC; spiritual teachings based on his insight into duḥkha ("suffering") & the end of dukkha (the state of Nirvana).

and see Chapter I, page 12, Chapter II page 81, Chapter III  page 111, Chapter  IV page 133,

 

Epicurus:

341–270 BC, Greek philosopher, founder of Epicureanism; he rejected Platonism, the aim of his philosophy was to help people attain a happy, tranquil life (ataraxia), of peace and freedom from fear and the absence of pain (aponia).

and see Chapter VI, page 203