Logic Philosophy Sound and unsound argument
- 1. ENGLISH 9
- 2. MOST ESSENTIAL LEARNING COMPETENCY •Judge the relevance and worth of ideas, soundness of author’s reasoning, and the effectiveness of the presentation
- 3. OBJECTIVES • Identify relevant sentences • Determine sound or unsound argument
- 5. • Relevance is the concept of one topic being connected to another topic in a way that makes it useful to consider the second topic when considering the first.
- 6. •Soundness is a technical term in logic. It is used to describe arguments whose forms are valid and whose premises are true. A valid argument form is one whose premises and conclusions is arranged such that truth in the premises is ineluctably transferred to the conclusion. Therefore, a sound argument must have a true conclusion.
- 7. •Premise - a previous statement or proposition from which another is inferred or follows as a conclusion. •Conclusion - Logical result of the relationship between the premises. Conclusions serve as the thesis of the argument.
- 8. WHAT IS AN ARGUMENT? • In the field of logic and philosophy, an argument is a series of statements intended to determine the degree of truth of another statement. Premises and conclusions are the building blocks of an argument. Premises are a series of statements that provide reasons or evidence to determine the truth of a conclusion. Therefore, an argument can have more than one premise. A conclusion in an argument is the main point the arguer is trying to prove. Thus, an argument has only one conclusion and one or more premises.
- 9. WHAT IS LOGIC? •Logic is reasoning conducted or assessed according to strict principles of validity.
- 10. WHAT IS PHILOSOPHY? •Philosophy is the study of the fundamental nature of knowledge, reality, and existence, especially when considered as an academic discipline.
- 11. WHAT IS AN ARGUMENT? • In the field of logic and philosophy, an argument is a series of statements intended to determine the degree of truth of another statement. Premises and conclusions are the building blocks of an argument. Premises are a series of statements that provide reasons or evidence to determine the truth of a conclusion. Therefore, an argument can have more than one premise. A conclusion in an argument is the main point the arguer is trying to prove. Thus, an argument has only one conclusion and one or more premises. Let’s look at an example:
- 12. EXAMPLE •Premise 1: No one under eighteen-years-old can vote. •Premise 2: Rogan is under eighteen. •Conclusion: Therefore, Rogan cannot vote.
- 13. WHAT IS A SOUND ARGUMENT? • An argument must fulfill two requirements in order to be considered as sound. One requirement is that the argument must be valid. An argument is valid when its conclusion follows logically from the premises. In other words, it is impossible for the premises of an argument to be true while the conclusion is false. The second requirement is that all its premises should be true. Thus, a sound argument is a valid argument that has true premises.
- 14. WHAT IS A SOUND ARGUMENT? • An argument must fulfill two requirements in order to be considered as sound. One requirement is that the argument must be valid. An argument is valid when its conclusion follows logically from the premises. In other words, it is impossible for the premises of an argument to be true while the conclusion is false. The second requirement is that all its premises should be true. Thus, a sound argument is a valid argument that has true premises.
- 15. THE FOLLOWING IS A SOUND ARGUMENT AS IT CONTAINS TRUE PREMISES AND IS VALID. •Premise 1: All men are mortal. •Premise 2: Socrates is a man. •Conclusion: Therefore, Socrates is mortal.
- 16. WHAT IS AN UNSOUND ARGUMENT? •An unsound argument is the opposite of a sound argument. Thus, an unsound argument can be either valid or invalid. However, if the argument is valid, it has at least one false premise in order to consider it as an unsound argument.
- 17. WHAT IS AN UNSOUND ARGUMENT? •An unsound argument is the opposite of a sound argument. Thus, an unsound argument can be either valid or invalid. However, if the argument is valid, it has at least one false premise in order to consider it as an unsound argument.
- 20. LET’S TRY THIS •Directions: Identify whether the given statements is a SOUND or UNSOUND Argument. Be ready to explain your answer.
- 21. #1 •Premise 1: All cows are mammals. •Premise 2: All dogs are mammals. •Conclusion: Therefore, dogs are cows.
- 22. •Premise 1: All cows are mammals. •Premise 2: All dogs are mammals. •Conclusion: Therefore, dogs are cows. •Explanation: The above argument contains true premises, but it is invalid since the conclusion doesn’t logically follow from the premises. Therefore, it is also an unsound argument.
- 23. #2 •Premise 1: All cats are pink. •Premise 2: Toffee is a cat. •Conclusion: Therefore, Toffee is pink.
- 24. •Premise 1: All cats are pink. •Premise 2: Toffee is a cat. •Conclusion: Therefore, Toffee is pink. •Explanation: The above is a valid argument too since the conclusion logically follows from the premises. However, the first premise is not true. Therefore, this is an unsound argument.
- 25. #3 •Premise 1: All tigers are mammals. •Premise 2: No mammals are creatures with scales. •Conclusion: Therefore, no tigers are creatures with scales.
- 26. •Premise 1: All tigers are mammals. •Premise 2: No mammals are creatures with scales. •Conclusion: Therefore, no tigers are creatures with scales. •Explanation: The above is a valid argument since the conclusion logically follows from the premises. All premises are true. Therefore, this is a sound argument.
- 27. SUMMARY SOUND VS UNSOUND ARGUMENT • Validity and the truth of the premises are the two factors that determine the soundness of an argument. A sound argument is an argument that is valid and has true premises while an unsound argument is an argument that is invalid or has at least one false premises. Thus, this is the key difference between sound and unsound argument.
- 29. THANK YOU!