PHIL 1500P Contemporary Moral, Social, & Religious Issues
Fall Lecture 3
What makes some arguments better than others?
- How arguments go wrong
- Implausible premises
- Weak connections
- Repairing arguments
How Arguments Go Wrong
STRUCTURE. Weak connected of premises to conclusion
FOUNDATIONS. Premises implausible (not believable)
- Plausibility of Premises
A claim is plausible if we have good reason to believe it is true
A claim is less plausible if we do not have or have less good reason to believe it’s true
- Two types of reason to accept, or reject, premises
Ex: Brothers are male siblings, and Sue once told me that Pat is her brother, so Pat must
be a guy. Brothers are male is logic. Told me that is evidence.
- Types of Evidence
Reliable personal experience. This means the person was in a position to clearly
perceive what happened and that the same person has clear recollection of this
Reliable testimony. This means that sources are able to know what they are talking
about (Eyewitness, experience over time, expert knowledge, or public organizations that
do any of the above) and there is no reason to doubt their honesty.
Common knowledge (Ex: Earth is not flat. Few people live to 100. There is a city called
“London” in England.)
- The “Balance of Reasons” Approach is when you mist compare each claim with the
contradictory claim. If the balance of reasons say it is true then a claim is plausible.
Ex. Premise: Every organism on Earth has a genetic code. This is a reliable testimony:
Biology, as taught in schools, which screen for reliable science.
Contradictory claim: Some organism on Earth does not have a genetic code. This
contradicts a well-confirmed theoretical principle of biology. Weak Connections
- Logical Connections
- Type 1 – “valid”.
Impossible: premises true + conclusion false
Premises steer us to the conclusion
Accepting the premises me