Poland Liceum ogólnokształcące, klasa II Philosophy (extended level)
Chapters: 2
1. Logical culture
Names, sentences and flaws of expression · Definitions · Direct and indirect justification · Errors in reasoning and fair discussion
- Logic: How Good Arguments Work – Logic studies good reasoning. An argument has premises (reasons) and a conclusion; inference is the step between them. In a deductive argument, if the premises are true the conclusion must be true; such an argument is valid, and it is sound if the premises really are true. One counterexample shows an argument form is invalid. Inductive arguments move from observed cases to a general or likely conclusion; they are strong or weak, never certain. Categorical propositions (A, E, I, O) and simple predicate logic (∀, ∃) help us write arguments precisely and spot fallacies.
- Logical Reasoning – Logical reasoning means getting from facts (premises) to a conclusion in a way we can check. A statement is either true or false. Statements are joined with NOT, AND, OR, IF…THEN and IF AND ONLY IF, and truth tables show when the result is true. In deduction, if the premises are true and the form is valid, the conclusion must be true (modus ponens, modus tollens, syllogisms). Venn diagrams test syllogisms with 'all', 'no' and 'some'. Induction and analogy go from examples to a general idea: the conclusion is only probable. A direct proof goes step by step from what is known; an indirect proof assumes the opposite and reaches a contradiction. Fallacies are tempting but faulty arguments.
- Logical Fallacies: How Good-Looking Arguments Go Wrong – A fallacy is an error in reasoning that makes an argument weak or invalid, even though it may look convincing. Formal fallacies are mistakes in the form (structure) of a deductive argument, such as affirming the consequent. Informal fallacies are mistakes in content, language or relevance, such as ad hominem, straw man, false dilemma, slippery slope, appeal to popularity or false authority, hasty generalisation, post hoc and circular reasoning. Spotting them helps us discuss fairly.
2. History of philosophy: antiquity and Middle Ages
Ancient philosophy · Thomas Aquinas
- Ancient Philosophy: From the First Questions to Stoicism – Philosophy means 'love of wisdom'. Around 600 BCE Greek thinkers began to explain nature by reason (logos) instead of myth. The Presocratics searched for the first principle (arche): water, air, fire, unchanging being or atoms. Then the Sophists and Socrates turned to human life, and Socrates died for his questioning (told in Plato's Apology). Plato taught the theory of Forms; Aristotle built logic and science from observation. Later Stoics, Epicureans and Cynics, and Romans like Cicero and Seneca, asked how to live a good, calm life.
- Medieval Philosophy: Faith and Reason from Augustine to Ockham – Medieval philosophy covers roughly 400 to 1450 CE. Its big question was how faith (what religion teaches) and reason (what we can work out by thinking) fit together. Augustine taught that truth is found within, lit by God, and that faith seeks understanding. Boethius passed on Greek logic. Islamic and Jewish thinkers such as Avicenna, Averroes and Maimonides studied Aristotle deeply, and their work reached Europe through Latin translations. In the new universities, scholasticism used a careful question-and-answer method. Anselm argued for God from the idea of the greatest possible being. Thomas Aquinas joined Aristotle with Christian faith: reason and faith are two floors of one house, and reason can show that a first cause exists (the five ways). In the 1300s William of Ockham urged simple explanations (Ockham's razor), and faith and reason began to separate, opening the way to the Renaissance and modern science.