Part V: Exercises

 In your own words, list and explain each version of Principle of Non-Contradiction

Answer the following questions.

1. Why does the example of an elder who claims to be both young and old not violate the Principle of Non-Contradiction?
2. What is the difference between the two versions of the doxastic interpretation?
3. Why is it fair to say that the semantic version of the principle can be treated as an extension of the metaphysical version?

(Challenge Question) Determine whether or not the following examples break a form of the Principle of Non-Contradiction and explain your reasoning. (Hint: In terms of the doxastic version of the principle, think of the second interpretation from above.)

Ex. Last time I saw my uncle, he was both sad and happy. He was sad because he lost his

favorite pair of shoes, but he was happy because he bought a new pair.

Answer: Does not break the Principle of Non-Contradiction, as he is happy and sad about two different things, so he does not possess these contrasting emotions in the same way. Also remember that “sad” and “happy” are opposites, not contradictories.

1. Last week, I encountered an individual who at the same time believed that the climate crisis is one of the world’s most pressing issues and that the fossil fuel industry is perfectly fine as it is.
2. One day, upon going to a second hand store, my friend and I saw a painting and simultaneously began to comment on it. I claimed that the picture was beautiful, while my friend claimed it was ugly.
3. Upon encountering a well-known liar, I began to have a conversation with them. Within the conversation, they said the sentence “I’m not lying”.