Theme 3.Both attacked the Stoics for asserting a criterion of truth in our knowledge; although their views were indeed skeptical, they seem to have considered that what they were maintaining was a genuine tenet of Socrates and Plato.Hence, logic (called by Epicurus (kanonikon), or the doctrine of canons of truth) is made entirely subservient to physics, physics to ethics The standards of knowledge and canons of truth in theoretical matters are the impressions of the senses, which are true and indisputable, together with the presentations formed from such impressions, and opinions extending beyond those impressions, as far as they are supported or not contradicted by the evidence of the senses.The followers of Aristotle, known as Peripatetics (Theophrastus of Lesbos, Eudemus of Rhodes, Strato of Lampsacus, etc.), to a great extent abandoned metaphysical speculation, some in favor of natural science, others of a more popular treatment of ethics, introducing many changes into the Aristotelian doctrine in a naturalistic direction.Epicurus's physics, in which he follows in essentials the materialistic system of Democritus, is intended to refer all phenomena to a natural cause, so that a knowledge of nature may set men free from the bondage of disquieting superstitions.In ethics, he followed, within certain limits, the Cyrenaic doctrine, conceiving the highest good to be happiness, and happiness to be found in pleasure, to which the natural impulses of everything are directed.The atomism of such presocratic philosophers as Leucippus and Democritus partly anticipated the corpuscularianism of the seventeenth century and modern physics

Agnosticism is the belief that human beings do not have sufficient evidence to warrant either the affirmation or the denial of a proposition.Stoicism

Such were the aims of Stoicism, founded by Athens around 310 by Zeno of Citium (in Cyprus), and brought to fuller systematic form by his successors, the heads of the school, Cleanthes of Assos, and especially Chrysippus of Soli, who died around 206.Ethics predominated both with the Cynics and Cyrenaics, although their positions were in direct opposition Antisthenes of Athens, the founder of the Cynics, conceived the highest good to be the virtue which spurns every enjoyment.Philosophy of Classical Greek Philosophy: Socrates, Plato, Aristotle.Philosophy of Ancient Greece

1.2.3.