Exercises for Informal Fallacies

1. We should let Tom graduate. It is because if he cannot graduate, he need study for one more semester. You know, Tom’s parents are quite old and expect him to have a job very soon.

2. Since we should be honest, you should tell how awful she looks today.

3. Why don’t you get an i-phone? Everyone has one now.

4. CY Leung is a lousy chief executive. We are now suffering from inflation, and terrorists are everywhere. Therefore, he must step down.

5. Mary dares to call me a liar! I have heard her lie to her friends before.

6. If the teachers of this college are so irresponsible, then it will be no wonder that their students are irresponsible. Now it is a fact that the teachers of this college are irresponsible. Therefore, it is no wonder that their students are irresponsible.

7. Long Hair always advocates that we should have a better welfare system. Obviously, he wants to get rid of CY Leung and the Chinese government altogether. Yet without a unified China and an Chief Executive, Hong Kong will not survive. None of us want Hong Kong not surviving. Therefore, agreeing with Long Hair’s proposal is like committing suicide.

8. Doctors always say that cigarette is bad to health. But think: there are a lot of unhealthy things in life. Perhaps we should avoid all unhealthy things including walking under an electric cable. How unfair that one might get brain cancer just by walking under a cable!

9. You just said that you have lost all your money in a poker game yesterday. So how could you say that I owed you money before?

10. It is strange to hear that USA makes complaint against China’s violation of human rights. We hear cases of USA violating the rights of black people too.

11. Two students of Centennial College were expelled for cheating. Centennial College is indeed a place for cheaters.

12. If a student has emotional problem in the middle of the night, his/her teacher is not obligated to offer him/her immediate counseling. Similarly, when the ferry accident occurred, CY Leung was not obligated to attend to this incident immediately.

13. The students’ request for the provision of an internship programme should be refused. If we grant this, they will ask us to reduce the school fee, and after that they will ask for free shuttle service. God knows how we can satisfy them!

14. You are the last one who used the photocopying machine. So you must have broken it.

15. No evidence shows that playing video games will increase one’s violent behavior. Thus playing video games will not increase one’s violent behavior.

16. We should help our friends. So if your friend asks to you to let him copy your homework, you should do so.

17. As TV watching has increased over the last decade, so has the crime rate. So TV producers must be responsible for the raise in crime rate.

18. Animals and humans are similar in many ways. Both have sensations, desires, fears, pleasures, and pains. Human have a right not to be subjected to needless pain. Does it follow that animals have a right not to be subjected to needless pain?

19. Tom has argued that the North East of the New Territory should not be developed. He must be nuts! If we are not going to develop any rural areas or reclaim any land, how can we have more land to build housing estates?

20. Substances will move from a region of higher concentration to lower concentration. So money will move from the rich to the poor.

21. Do you feel guilty about what you have done?

22. Of course abortion is permissible. After all, a woman has a right to do as she pleases with her own body.

23. Students are either diligent or lazy. Diligent students do not need encouragement. It is no use to encourage lazy students. Therefore, there is no need to encourage students.

24. All laws have a lawmaker. Natural laws are laws. Therefore, natural laws have a lawmaker, i.e., God.

25. John studies in Centennial College. Since Centennial College is a bad college, John must be a bad student.

26. I have asked you to loan me $100. You have only loaned me $50. So you still owe me $50. Since I have borrowed $50 from you, I also owe you $50. Since we owe each other $50, no one need to pay each other.

27. Every gene is selfish; they will try to perpetuate itself by whatever means. Therefore, every human is selfish; they will try to strive for survival by whatever means.

28. Each human cell has 70% carbon. Therefore, the whole human body has 70% carbon.