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My Favorite Russian Joke. A Russian Woman borrows a teapot from her neighbor. She returns it broken, and the neighbor sues. In court, the woman makes three statements in her defense:. My Favorite Russian Joke. I never borrowed the pot. My Favorite Russian Joke. I never borrowed the pot.
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My Favorite Russian Joke • A Russian Woman borrows a teapot from her neighbor. She returns it broken, and the neighbor sues. In court, the woman makes three statements in her defense:
My Favorite Russian Joke • I never borrowed the pot.
My Favorite Russian Joke • I never borrowed the pot. • When I borrowed the teapot, it was already broken.
My Favorite Russian Joke • I never borrowed the pot. • When I borrowed the teapot, it was already broken. • When I gave it back, it was undamaged.
Nobody knows the future/God is omniscient. • I can choose what to eat for breakfast tomorrow/God knows what I will choose.
Nobody knows the future/God is omniscient. • I can choose what to eat for breakfast tomorrow/God knows what I will choose.
Abortion is wrong because it is always wrong to take a human life/Capital punishment is a just punishment for murder
Abortion is wrong because it is always wrong to take an innocent human life/Capital punishment is a just punishment for murder
I am the same person that I was when I was five years old/Everything changes
I am the same person that I was when I was five years old/Everything changes • No animal has a soul/Humans are animals
Necessary and Sufficient Conditions • These terms refer to relations between facts.
Necessary Conditions • A condition q is necessary for p if it is impossible for something to be p without being q.
Necessary Conditions Example: Being an animal is a necessary condition for being a mammal.
Necessary Conditions Example: Being an animal is a necessary condition for being a mammal. Being married is a necessary condition for getting a divorce.
A Diagram of Necessary Conditions Everything inside the large circle is an animal; nothing outside the large circle is an animal. Animals Mammals
A Diagram of Necessary Conditions Everything inside the large circle is an animal; nothing outside the large circle is an animal. Everything inside the small orange circle is a mammal; nothing outside the small circle is an animal. Animals Mammals
A Diagram of Necessary Conditions Everything inside the large circle is an animal; nothing outside the large circle is an animal. Everything inside the small orange circle is a mammal; nothing outside the small circle is an animal. Since the small circle is entirely enclosed within the large one, you can say that it has to be animal if it is a mammal. Animals Mammals
A Diagram of Necessary Conditions Everything inside the large circle is an animal; nothing outside the large circle is an animal. Everything inside the small orange circle is a mammal; nothing outside the small circle is an animal. Since the small circle is entirely enclosed within the large one, you can say that it has to be animal if it is a mammal. Thus, being an animal is a necessary condition for being a mammal. Animals Mammals
Sufficient Conditions • A condition p is sufficient for q if it is impossible for something to be p without being q.
Example of sufficient condition • Being a mammalis a sufficient condition for being an animal, because it is impossible for something to be a mammal and not be an animal.
Example of sufficient condition • . Put slightly different, if you know p is a mammal, that’s enough to know that p is an animal. Animals Mammals
Example of sufficient condition • . Put slightly different, if you know p is a mammal, that’s enough to know that p is an animal. Animals Mammals
Food 4 Thought • Being an animal is a _______ condition for being a monkey.
Food 4 Thought • Being an animal is a necessary condition for being a monkey.
Food 4 Thought • Being an animal is a necessary condition for being a monkey. • Being a grandfather is a ________ condition for being a father.
Food 4 Thought • Being an animal is a necessary condition for being a monkey. • Being a grandfather is a sufficient condition for being a father.
Food 4 Thought • Being an animal is a necessary condition for being a monkey. • Being a grandfather is a sufficient condition for being a father.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. John behaves as if he is completely drunk. Therefore: John is not responsible for his actions.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Inductive
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Inductive • “as if” indicates probability rather than logical certainty.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Deductive
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Deductive • 1. All D = N
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Deductive • 1. All D = N • 2. J = D.
Deductive Or Inductive? • A completely drunk person is not responsible for his actions. • John behaves as if he is completely drunk. • Therefore: John is not responsible for his actions. • Deductive • 1. All D = N • 2. J = D. • 3. Therefore: J = N.
Deductive or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. Human cloning is certainly not a blessing for humanity. So human cloning immoral.
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity.
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. • Human cloning is certainly not a blessing for humanity.
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. • Human cloning is certainly not a blessing for humanity. • So human cloning immoral.
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. • Human cloning is certainly not a blessing for humanity. • So human cloning immoral. • Deductive • 1. Either I or B
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. • Human cloning is certainly not a blessing for humanity. • So human cloning immoral. • Deductive • 1. Either I or B • 2. Not B.
Deductive Or Inductive? • Either human cloning is immoral, or it will be a blessing for humanity. • Human cloning is certainly not a blessing for humanity. • So human cloning immoral. • Deductive • 1. Either I or B • 2. Not B. • 3. Therefore: I.
Valid or Not? • If the premises of a deductive argument are true, then the conclusive must be true.
Valid or Not? • No government has the right to force people to pay taxes. • Therefore: The U.S. Government has no right to force people to pay taxes.
Valid or Not? • No government has the right to force people to pay taxes. • Therefore: The U.S. Government has no right to force people to pay taxes. • Valid
Valid or Not? • No government has the right to force people to pay taxes. • Therefore: The U.S. Government has no right to force people to pay taxes. • Valid • All G = ~R.
Valid or Not? • No government has the right to force people to pay taxes. • Therefore: The U.S. Government has no right to force people to pay taxes. • Valid • All G = ~R. • U = G.
Valid or Not? • No government has the right to force people to pay taxes. • Therefore: The U.S. Government has no right to force people to pay taxes. • Valid • All G = ~R. • U = G. • Therefore: U = ~R