Phi 104 A Concise Introduction to Logic
A Concise Introduction to Logic. The following arguments are deductive. Determine whether each is valid or in-valid, and note the relationship between your answer and the truth or falsity of the premises and conclusion. Finally, determine whether the argument is sound or unsound.
★1. Since Moby Dick was written by Shakespeare, and Moby Dick is a science-
fiction novel, it follows that Shakespeare wrote a science-fiction novel.
- Since London is north of Paris and south of Edinburgh, it follows that Paris is south of Edinburgh.
- If George Washington was beheaded, then George Washington died. George
Washington died. Therefore, George Washington was beheaded.
★4. The longest river in South America is the Amazon, and the Amazon flows
through Brazil. Therefore, the longest river in South America flows through
- Since the Spanish-American War occurred before the U.S. Civil War, and the
U.S. Civil War occurred after the Korean War, it follows that the Spanish-American War occurred before the Korean War.
- The Empire State Building is taller than the Statue of Liberty, and the Statue of Liberty is taller than the Eiffel Tower. Therefore, the Empire State Building is taller than the Eiffel Tower.
★7. All leopards with lungs are carnivores. Therefore, all leopards are carnivores.
- Chicago is a city in Michigan and Michigan is part of the United States. Therefore, Chicago is a city in the United States.
- If President Barack Obama was born in Massachusetts, then he is a native of New England. Barack Obama is not a native of New England. Therefore, Barack Obama was not born in Massachusetts.
★10. Every province in Canada has exactly one city as its capital. Therefore, since there are thirty provinces in Canada, there are thirty provincial capitals.
- Since the Department of Defense Building outside Washington, D.C., has the
shape of a hexagon, it follows that it has seven sides.
- Since Winston Churchill was English, and Winston Churchill was a famous statesman, we may conclude that at least one Englishman was a famous statesman.
★13. Since some fruits are green, and some fruits are apples, it follows that some fruits are green apples.
- All physicians are individuals who have earned degrees in political science, and some lawyers are physicians. Therefore, some lawyers are persons who have earned degrees in political science.
- The United States Congress has more members than there are days in the year.
Therefore, at least two members of Congress have the same birthday.