Logic Presentation

Let's talk about

LOGIC

(LOGOS)

Start

Here is how we are going to break this down!

Why logic is important

What are the rules?

History

History

"The line has magnitude in one way, the plane in two ways, and the solid in three ways, and beyond these there is no other magnitude because the three are all."Aristotle

The birth of logic

Aristotle (384-322 BCE) was a Greek philosopher who is widely regarded as the founder of formal logic. He developed his theory of logic in his six-part book called The Organon, which contains his works on categories, propositions, syllogisms, fallacies, scientific method, and rhetoric. Aristotle’s logic was based on his observation and analysis of natural language and argumentation. He devised a system of rules and strategies for deductive reasoning that was influential for more than 2000 years

Aristotle 384-322 BCE

Aristotle’s theory of term logic or syllogism is a system of deductive reasoning that consists of three sentences: two premises and a conclusion. The premises and the conclusion are categorical propositions that relate two terms (subject and predicate) by using one of four types of quantifiers: universal affirmative (all), universal negative (no), particular affirmative (some), or particular negative (not all). The validity of a syllogism depends on its form or structure, not its content or meaning

EXAMPLES

All humans are mortal. Socrates is a human. Therefore, Socrates is mortal. (This is a valid syllogism in the first figure with universal affirmative premises and a universal affirmative conclusion.) No reptiles have fur. Some snakes are reptiles. Therefore, some snakes do not have fur. (This is a valid syllogism in the second figure with universal negative premises and a particular negative conclusion.)

Aristotle is the founder of "Western" Logic ...

These are Eastern sources that also define logic

Chanakya (c. 350-283 BCE), who described logic as an independent field of inquiry called anviksiki. Vaisheshika school (c. 2nd century BCE - 2nd century CE), which developed a system of categories, inference, and atomism. Nyaya school (c. 6th century BCE - 2nd century CE), which elaborated on the rules of inference, debate, and fallacies. Jain school (c. 6th century BCE - present), which proposed a multi-valued logic called saptabhangi that allows for seven possible judgments on any proposition. Buddhist school (c. 5th century BCE - present), which challenged and refined the logical theories of other schools and introduced concepts such as emptiness, dependent origination, and four-cornered negation1. Mohist school (c. 5th century BCE - 3rd century BCE), which advocated for a pragmatic and consequentialist approach to logic and reasoning. School of Names (c. 4th century BCE - 3rd century CE), which explored paradoxes, linguistic analysis, and sophistry.

What are the rules?

• The law of non-contradiction: A statement cannot be both true and false at the same time and in the same way. For example, it cannot be true that “it is raining” and “it is not raining” at the same time and place.
• The law of excluded middle: A statement is either true or false, there is no third option. For example, it is either true or false that “there is life on Mars”, there is no other possibility.
• The principle of identity: A thing is what it is, and not something else. For example, “a cat is a cat” and not a dog or a bird.
• The principle of bivalence: Every statement has exactly one truth value, either true or false. For example, “the sky is blue” has one truth value (true), while “the sky is green” has another truth value (false).
• The principle of non-circularity: An argument cannot use its conclusion as one of its premises. For example, “God exists because God exists” is a circular argument.

What is NOT logic (fallacies)

Ad hominem: attacking the person rather than their argument Red herring: introducing an irrelevant topic to divert attention from the original issue Straw man: misrepresenting or exaggerating an opponent’s position to make it easier to refute Equivocation: using ambiguous or unclear language to confuse or deceive Slippery slope: assuming that a small step will inevitably lead to a larger and undesirable consequence Hasty generalization: drawing a conclusion based on insufficient or biased evidence Appeal to authority: relying on an expert or a source that is not credible or relevant False dilemma: presenting only two options when there are more possibilities

Who cares?

Logic is important because it influences every decision we make in our lives. Logical thinking allows us to learn and make decisions that will affect our lifestyle1. Logic also helps us with problem-solving, reasoning, and communication. Logic is a vital part of your everyday life. Logic is also a branch of philosophy that studies what constitutes valid and good reasoning. Logic helps us to evaluate arguments and avoid fallacies. Logic also helps us to understand different forms of reasoning, such as deductive, inductive, abductive, etc.

- Genially

Improve your logic skills

Spend time on creative hobbies, such as drawing, painting, writing, playing music, etc. These activities can stimulate your brain and help you develop problem-solving abilities. Practice questioning everything you see, hear, or read. Ask yourself what evidence supports or contradicts a claim, what assumptions are being made, what alternatives are possible, etc. This can help you avoid fallacies and biases. Socialize with others who have different perspectives and opinions. Listen to their arguments and try to understand their reasoning. This can help you expand your horizons and learn from others. Learn a new skill or a foreign language. This can challenge your mind and improve your memory and concentration. It can also expose you to new cultures and ways of thinking. Try to anticipate the outcome of your decisions before you make them. Think about the possible consequences and benefits of each option. Use logic to weigh the pros and cons. Notice patterns in your personal life, work, or media. Try to explain why they occur and what they mean. Use logic to test your hypotheses and predictions. Play logic games or puzzles that require deductive, inductive, or abductive reasoning. These can sharpen your logical thinking skills and make them more fun