Title: Sec. 3.6 Euler Circles and Syllogistic Arguments
1Sec. 3.6 Euler Circles and Syllogistic Arguments
2Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
3Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
The premise is ALWAYS true
4Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
5Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
6Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All ostriches are birds
All ostriches sing
7Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All ostriches are birds
All ostriches sing
Birds
8Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All ostriches are birds
All ostriches sing
Birds
Sing
9Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All ostriches are birds
All ostriches sing
Birds
Ostriches
Sing
10Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All ostriches are birds
All ostriches sing
Birds
Ostriches
Sing
VALID
11Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All animals with wings can fly
All ostriches are birds
Birds have wings
All ostriches sing
Birds can fly
Birds
Ostriches
Sing
VALID
12Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All animals with wings can fly
All ostriches are birds
Birds have wings
All ostriches sing
Birds can fly
Animals with wings
Birds
Ostriches
Sing
VALID
13Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All animals with wings can fly
All ostriches are birds
Birds have wings
All ostriches sing
Birds can fly
Animals with wings
Birds
Ostriches
Sing
Fly
VALID
14Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All animals with wings can fly
All ostriches are birds
Birds have wings
All ostriches sing
Birds can fly
Animals with wings
Birds
Ostriches
Birds
Sing
Fly
VALID
15Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All birds sing
All animals with wings can fly
All ostriches are birds
Birds have wings
All ostriches sing
Birds can fly
Animals with wings
Birds
Ostriches
Birds
Sing
Fly
VALID
VALID
16Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
Rhinos have wings
Rhinos can fly
17Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
Rhinos have wings
Rhinos can fly
Animals with wings
18Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
Rhinos have wings
Rhinos can fly
Animals with wings
Fly
19Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
Rhinos have wings
Rhinos can fly
Animals with wings
Rhinos
Fly
20Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
Rhinos have wings
Rhinos can fly
Animals with wings
Rhinos
Fly
VALID
21Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
All watermelons are edible
Rhinos have wings
Some edible foods are fruits
Rhinos can fly
All watermelons are fruits
Animals with wings
Rhinos
Fly
VALID
22Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
All watermelons are edible
Rhinos have wings
Some edible foods are fruits
Rhinos can fly
All watermelons are fruits
Animals with wings
Rhinos
Watermelons
Fly
VALID
23Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
All watermelons are edible
Rhinos have wings
Some edible foods are fruits
Rhinos can fly
All watermelons are fruits
Animals with wings
Rhinos
Watermelons
Edible
Fly
VALID
24Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
All watermelons are edible
Rhinos have wings
Some edible foods are fruits
Rhinos can fly
All watermelons are fruits
Animals with wings
Rhinos
Watermelons
Edible
Fly
VALID
Fruits
25Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All animals with wings can fly
All watermelons are edible
Rhinos have wings
Some edible foods are fruits
Rhinos can fly
All watermelons are fruits
Animals with wings
Rhinos
Watermelons
Edible
Fly
VALID
Fruits
26Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All rich people are doctors
All car mechanics are doctors
27Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All rich people are doctors
All car mechanics are doctors
Car mechanics
28Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All rich people are doctors
All car mechanics are doctors
Rich
Car mechanics
29Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All rich people are doctors
All car mechanics are doctors
Rich
Car mechanics
Doctors
30Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All rich people are doctors
All car mechanics are doctors
Rich
Car mechanics
Doctors
VALID
31Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All X's are Y's
All rich people are doctors
Some Y's are Z's
All car mechanics are doctors
Some X's are Z's
Rich
Car mechanics
Doctors
VALID
32Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All X's are Y's
All rich people are doctors
Some Y's are Z's
All car mechanics are doctors
Some X's are Z's
Rich
Car mechanics
Xs
Doctors
VALID
33Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All X's are Y's
All rich people are doctors
Some Y's are Z's
All car mechanics are doctors
Some X's are Z's
Rich
Ys
Car mechanics
Xs
Doctors
VALID
34Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All X's are Y's
All rich people are doctors
Some Y's are Z's
All car mechanics are doctors
Some X's are Z's
Rich
Ys
Car mechanics
Xs
Zs
Doctors
VALID
35Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All car mechanics are rich
All X's are Y's
All rich people are doctors
Some Y's are Z's
All car mechanics are doctors
Some X's are Z's
Rich
Ys
Car mechanics
Xs
Zs
Doctors
VALID
36Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All astronauts can fly
Some pilots are astronauts
37Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All astronauts can fly
Some pilots are astronauts
Pilots
38Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All astronauts can fly
Some pilots are astronauts
Fly
Pilots
39Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All astronauts can fly
Some pilots are astronauts
Fly
Astronauts
Pilots
40Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All astronauts can fly
Some pilots are astronauts
Fly
Astronauts
Pilots
41Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All birds sing
All astronauts can fly
All canaries sing
Some pilots are astronauts
Some canaries are birds
Fly
Astronauts
Pilots
42Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All birds sing
All astronauts can fly
All canaries sing
Some pilots are astronauts
Some canaries are birds
Fly
Astronauts
Birds
Pilots
43Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All birds sing
All astronauts can fly
All canaries sing
Some pilots are astronauts
Some canaries are birds
Sings
Fly
Astronauts
Birds
Pilots
44Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All birds sing
All astronauts can fly
All canaries sing
Some pilots are astronauts
Some canaries are birds
Sings
Fly
Canaries
Astronauts
Birds
Pilots
45Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All pilots can fly
All birds sing
All astronauts can fly
All canaries sing
Some pilots are astronauts
Some canaries are birds
Sings
Fly
Canaries
Astronauts
Birds
Pilots
46Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
47Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
Horses
48Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
Animals with 4 legs
Horses
49Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
Animals with 4 legs
Can fly
Horses
50Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
Animals with 4 legs
Can fly
Horses
VALID
51Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
No horses can fly
Horses
Animals with 4 legs
Can fly
Horses
VALID
52Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
Animals with 4 legs
No horses can fly
Horses
Animals with 4 legs
Can fly
Horses
VALID
53Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
Animals with 4 legs
No horses can fly
Horses
Cannot fly
Animals with 4 legs
Can fly
Horses
VALID
54Sec. 3.6 Euler Circles and Syllogistic Arguments
Def Deductive reasoning is the process of using
logic to reason to a necessary and
inescapable conclusion from a given set
of premises
An argument is VALID if the conclusion is ALWAYS
true
The premise is ALWAYS true
Determine whether the following arguments are
valid or invalid.
All horses have 4 legs
No animals with four legs can fly
Animals with 4 legs
No horses can fly
Horses
Cannot fly
Animals with 4 legs
Can fly
Horses
VALID
VALID