Plato 
Apology, Crito, Phaedo [EPUB ebook] 

Of all writers of speculative philosophy, both ancient and modern, there is probably no one who has attained so eminent a position as Plato. What Homer was to Epic poetry, what Cicero and Demosthenes were to oratory, and what Shakespeare was to the drama of England, Plato was to ancient philosophy, not unapproachable nor unapproached, but possessing an inexplicable but unquestioned supremacy.