Identify which of the following propositions are a priori and which are a posteriori.

1. "Every widower has lost a spouse." (Answer: a priori)

2. "Most widows do not remarry." (Answer: a posteriori)

3. "The moon is made of green cheese." (Answer: a posteriori)

4. "7 + 5 = 12." (Answer: a priori)

5. "If anything is colored it is extended." (Answer: a priori)

6. "If anything is colored it is attractive." (Answer: a posteriori)

7. "In a plane, a circle encloses a larger area than any other figure of equal perimeter." (Answer: a priori)

8. "Every effect must have a cause." (Answer: a priori)

9. "All U.S. citizens are mortal." (Answer: a posteriori)

10. "Everything that is mortal is subject to death." (Answer: a priori)

11. "You can fool all of the people some of the time, and some of the people all of the time, but you can't fool all of the people all of the time." (Answer: a posteriori)

12. "If some of the people are fooled all of the time, then at no time are all of the people free of deception." (Answer: a priori)