
Valid Argument
Is an argument in which it is impossable for the conclusion to be false given that the premises are true.

Invalid Argument
A deductive argument in which it is possable for the conclusion to be false given that the premises are true.

Sound argument
A deductive argument tht is valid and has all true premises.

Unsound argument
A deductive argument

Strong (inductive) argument
An inductive argument in which it is improbable that the conclusion be false given that the premises are true.

Weak (inductive) argument
An inductive argument in which the conclusion does not follow probably from the premises even though it is claimed to do so.

Cogent argument
An inductive argument that is strong, has all true premises, and meets the total evidence requirement.

Uncogent argument
An inductive argument that is weak, has one or more false premises, fails to meet the total evidence requirement, of any combination of these.


Modus Ponens (MP)
 If ...then

Deductive Arguments (table)

Mobile chart of arguments(?)

Determinw whether the following arguments are inductive or deductive.
1) Since Tom is the brother of Agatha, and Agatha is the mother of Raquel, it follows that Tom is the uncle of Raquel.
Deductive

Determinw whether the following arguments are inductive or deductive.
2) When a cook cannot recall the ingredients in a recipe, it is appropriate that she refresh her memory by consulting the recipe book. Similarly, when a student cannot recall the answers during a final exam, it is appropriate that she refresh her memory by consulting the textbook.
Inductive

Determinw whether the following arguments are inductive or deductive.
3) The broadway Theater marquee says that The Phantom of the Opera is playing nightly. Therefore it must be that case that The Phantom of the Opera is playing there tonight.
Inductive.

Determinw whether the following arguments are inductive or deductive.
4) Since Christmas is always on a Thursday, it follows that the day after Christmas is always on a Friday.
Deductive.

Determinw whether the following arguments are inductive or deductive.
5) Suppose figure A is a triangle having two equal angles. It follows that figure A has two equal sides.
Deductive.

Determinw whether the following arguments are inductive or deductive.
6) By accident Karen baked her brownies two hours longer than she should have. Therefore, they have probably been ruined.
Inductive.

Determinw whether the following arguments are inductive or deductive.
7) After taking LSD, Alice said she saw a UFO land in the shopping center parking lot. Since Alice has a reputation for always telling the truth, wemust conclude that a UFO really did land land there.
Inductive.

Determinw whether the following arguments are inductive or deductive.
8) Since Phyllis is the cousin of Denise, and Denise is the cousin of Harriet, it follows necessaily that Harriet is the cousin of Phyllis.
Deductive.

Determinw whether the following arguments are inductive or deductive.
9) The picnic scheduled in the park for tomorrow will most likely be cancled. It's been snowing for six days straight.
Inductive.

Determinw whether the following arguments are inductive or deductive.
10) Circle A has exactly twice the diameter of circle B. From this we may conclude that circle A has exactly twice the area of circle B.
Deductive.

Determinw whether the following arguments are inductive or deductive.
11) Robert has lost consistantly at blackjack everyday for the past several days. Therefore, it is very likely that he will win today.
Inductive.

Determinw whether the following arguments are inductive or deductive.
12) Since John loves Nancy and Nancy loves Peter, it follows necessarily that John loves Peter.
Deductive.

Determinw whether the following arguments are inductive or deductive.
13) This cash register contains over 100 coins. Three coins selected at random were found to have dates earlier then 1960. Therefore, probably all of the coins in the drawer have dates earlier than 1960.
Inductive.

Determinw whether the following arguments are inductive or deductive.
14) The Japanese attack on Pearl Harbor happened in either 1941 or 1951. But it didn't happen in 1941. Therefore, it happened in 1951.
Deductive.

Determinw whether the following arguments are inductive or deductive.
15) Harry will never be able to solve that difficult problem in advanced calculus in the limited time allowed. He has never studied anything beyond algerbra, and in that he earned only a C.
Inductive.

Determinw whether the following arguments are inductive or deductive.
16) Since x + y = 10, and x = 7. it follows that y = 4.
Deductive.

Determinw whether the following arguments are inductive or deductive.
17) If acupuncture is hocus pocus, then, acupuncture cannot relieve chronic pain. But acupuncture can relieve chronic pain. Therefore, acupuncture is not hocus pocus.
Deductive.

Determinw whether the following arguments are inductive or deductive.
18) If inflation heats up, then interest rates will rise. If interest rates rise, then bond prices will decline. Therefore, if inflation heats up, then bond prices will decline.
Deductive.

Determinw whether the following arguments are inductive or deductive.
19) Statistics reveal that 86% of those who recieve flu shots do not get the flu. Jack recieved a flu shot one month ago. Therefore, he should be immune, even though the flu is going around now.
Inductive.

Determinw whether the following arguments are inductive or deductive.
20) Since Michael is a Pisces, it necessarily follows that he was born in March.
Deductive.

Answer "true" or "False" to the following statement:
1) Some arguments, while not completely valid, are almost valid.
2) Inductive arguments admit of varying degrees of strength and weakness.
3) Invalid deductive arguments are basically the sasme as inductive arguments.
4) If a deductive argument has true premises and a false conclusion, it is necessarily invslid.
5) A valid argument may have a false premise and a false conclusion.
 1) Some arguments, while not completely valid, are almost valid. False
 2) Inductive arguments admit of varying degrees of strength and weakness. True
 3) Invalid deductive arguments are basically the sasme as inductive arguments. False
 4) If a deductive argument has true premises and a false conclusion, it is necessarily invslid. True
 5) A valid argument may have a false premise and a false conclusion. True

Answer "true" or "False" to the following statement:
6) A valid argument may have a false premise and a true conclusion.
7) A sound argument may be invalid.
8) A sound argument may have a false conclusion.
9) A strong argument may have false premises and a probably false conclusion.
10) A strong argument may have true premises and a probably false conclusion.
 6) A valid argument may have a false premise and a true conclusion. True
 7) A sound argument may be invalid. False
 8) A sound argument may have a false conclusion. False
 9) A strong argument may have false premises and a probably false conclusion. True
 10) A strong argument may have true premises and a probably false conclusion. False

Answer "true" or "False" to the following statement:
11) A cogent argument may have a probably false conclusion.
12) A cogent argument must be inductively strong.
13) If an argument has true premises and a true conclusion, we know that it is a perfectly good argument.
14) A statement may legitimately be spoken of as "valid" or "invalid".
15) An argument may legitimately be spoken of as "true" or " false".
 11) A cogent argument may have a probably false conclusion. False
 12) A cogent argument must be inductively strong. True
 13) If an argument has true premises and a true conclusion, we know that it is a perfectly good argument. False
 14) A statement may legitimately be spoken of as "valid" or "invalid". False
 15) An argument may legitimately be spoken of as "true" or " false".False

