Categorical
Logic – A
branch of formal logic in which the basic logical terms are all, some,
no, are, and not.
Propositional
Logic –
Deals with the relationships that hold between simple propositions or
statements and their compounds. The basic logical terms are not, or,
and, and if then.
Denying a
Statement
P ~P
T F
F T
|
Conjunction
P Q P & Q
|
Disjunction
P Q P or Q
|
Conditional
P Q P, Q
|
Consequent – What is supposed to follow from the antecedent
Conditionals assert neither the antecedent nor the consequent. Rather they express a link between the two; they claim that if the antecedent is true, then so is the consequent.
Types of Conditionals
|
True
by Definition |
If
a person has a mortgage on his house, he has borrowed money to buy the house. |
|
True
by Logic or Mathematics |
If
you add two and three you will get 5 |
Causal Relationship |
·
If a person cannot pay his mortgage his house will be confiscated. ·
If I drop this ball it will fall. ·
If a person has trouble paying his mortgage he is likely to be under
stress. |
|
Normative
Claim |
If
a person has incurred a debt by taking out a mortgage, he should make every
reasonable effort to repay that debt. |
|
Threat/Promise |
·
If you don’t get that next payment in, we’re going to have the locks
changed. ·
If you give me a kiss I will give you a raise |
“Either
it is an accident that I choose to act as I do or it is not. If it is an accident, then it is merely a
matter of chance that I did not choose otherwise; and if it is merely a matter
of chance that I did not choose otherwise, it is surely irrational to hold me
morally responsible for choosing as I did. But if it is not an accident that I
choose to do one thing rather than another, then presumably there is some
causal explanation of may choice: and if that case we are led back to
determinism [which would mean that we aren’t morally responsible for what we
do].”--A.J. Ayer: Freedom and Necessity