Curso completo, Raciocínio Lógico, Concursos Públicos 2019 - Prof Pedro Evaristo, Aula 11

Summary

In this 11th web class, the instructor delves into the topic of logical argumentation, emphasizing the importance of changing oneself through actions. The lesson introduces the concepts of conjunction, disjunction, and conditional statements, using everyday examples to clarify their meanings and applications. The instructor also explains the structure of a valid argument, consisting of premises leading to a conclusion, and contrasts it with invalid arguments that result in contradictions. The class aims to enhance students' logical thinking skills, applicable beyond exams to everyday problem-solving.

Takeaways

• 🎓 The lesson focuses on logical reasoning and argumentation, building on previous lessons.
• 💡 Key concept: 'We are what we do, but we are mainly what we do to change who we are.'
• 🔍 Emphasis on how logical reasoning enhances thinking ability beyond exam preparation.
• 🧩 Understanding conjunctions: 'and' statements are true only if both propositions are true.
• 🤔 Clarification on non-exclusive disjunctions: 'or' means at least one proposition is true.
• 🚫 Explanation of exclusive disjunctions: 'either/or' implies only one proposition is true, not both.
• ➡️ Conditional statements: 'if...then' relationships and their implications are discussed.
• ↔️ Biconditional statements: 'if and only if' relationships indicate mutual conditions.
• 📜 Argumentation basics: premises lead to a conclusion; valid arguments logically follow from true premises.
• ❌ Examples of invalid arguments: contradictions and erroneous conclusions are illustrated.

Q & A

What is the main topic of the 11th web class?

The main topic of the 11th web class is logical argumentation, discussing the process of argumentation and its importance in logical reasoning.

What is the philosophical thought shared at the beginning of the class?

The philosophical thought shared is that we are what we do, but we are mainly what we do to change what we are. It reflects the idea that our actions now are aimed at changing who we are.

How does the script define conjunction in logical argumentation?

In logical argumentation, conjunction is defined as a statement where both propositions must be true for the overall statement to be true, such as 'Felipe is a pilot and Diego is a tennis player.'

What is the difference between inclusive and exclusive disjunction in the context of the script?

Inclusive disjunction (or) means at least one of the propositions is true, while exclusive disjunction (or) with a line underneath implies that only one of the propositions is true, not both.

How is a conditional statement described in the script?

A conditional statement, such as 'If it's sunny, then I will go to the beach,' is described as a promise of an action if a condition is met, without guaranteeing the action if the condition is not met.

What is the meaning of a biconditional statement in the script?

A biconditional statement, such as 'If and only if it's sunny, then I will go to the beach,' means that the action (going to the beach) is a direct consequence of the condition (it being sunny) and vice versa.

What is an argumentation according to the script?

Argumentation is based on premises and a conclusion. It is a philosophical thought where the premises are accepted as true and lead to a conclusion.

What is an example of a valid argument given in the script?

An example of a valid argument is 'Every man is mortal. I am a man. Therefore, I am mortal.' The premises lead to a logically sound conclusion.

How is an invalid argument characterized in the script?

An invalid argument is characterized by leading to a false conclusion or a contradiction, such as claiming it is Monday and Tuesday at the same time.

What is the importance of logical reasoning in mathematics according to the script?

According to the script, logical reasoning in mathematics is important as it enhances one's thinking ability and helps in problem-solving, regardless of the context.

What is the final message conveyed in the script to the students?

The final message is an encouragement to continue practicing logical reasoning as it is a mental exercise that will be beneficial in their future encounters and endeavors.