LogicLogic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or logical truths. It studies how conclusions follow from premises due to the structure of arguments alone, independent of their topic and content. Informal logic is associated with informal fallacies, critical thinking, and argumentation theory. It examines arguments expressed in natural language while formal logic uses formal language.
ChrysippusChrysippus of Soli (kraɪˈsɪpəs,_krɪ-; Χρύσιππος ὁ Σολεύς, Chrysippos ho Soleus; 279 – 206 BC) was a Greco-Phoenician Stoic philosopher. He was a native of Soli, Cilicia, but moved to Athens as a young man, where he became a pupil of the Stoic philosopher Cleanthes. When Cleanthes died, around 230 BC, Chrysippus became the third head of the Stoic school. A prolific writer, Chrysippus expanded the fundamental doctrines of Cleanthes' mentor Zeno of Citium, the founder and first head of the school, which earned him the title of the Second Founder of Stoicism.
Disjunctive syllogismIn classical logic, disjunctive syllogism (historically known as modus tollendo ponens (MTP), Latin for "mode that affirms by denying") is a valid argument form which is a syllogism having a disjunctive statement for one of its premises. An example in English: The breach is a safety violation, or it is not subject to fines. The breach is not a safety violation. Therefore, it is not subject to fines. In propositional logic, disjunctive syllogism (also known as disjunction elimination and or elimination, or abbreviated ∨E), is a valid rule of inference.
EpictetusEpictetus (ˌɛpɪkˈtiːtəs, ; Ἐπίκτητος, Epíktētos; 50 135 AD) was a Greek Stoic philosopher. He was born into slavery at Hierapolis, Phrygia (present-day Pamukkale, in western Turkey) and lived in Rome until his banishment, when he went to Nicopolis in northwestern Greece for the rest of his life. His teachings were written down and published by his pupil Arrian in his Discourses and Enchiridion. Epictetus taught that philosophy is a way of life and not simply a theoretical discipline.