I'm pretty new to logic. I recently purchased "A Concise Introduction to Logic" by Patrick Hurley based on reviews. So far I'm liking the book. I'm really focusing hard on the first chapter to get a good foundation, and I have a concern: if premises must also be a valid conclusion with valid premises, can we ground truth on anything?
Using an example from the book:
All film stars are celebrities. Halle Berry is a film star. Therefore, Halle Berry is a celebrity.
So, I'm thinking of two scenarios about how the premises are considered. The first is a matter of definition. By the way we define "film stars" and "celebrities" the state of being verb "are" simply draws our attention to the state condition that "A" is "B".
The other scenario I envision is where each premise must also be a valid conclusion:
Someone known by many people in the public is a celebrity. Film stars are known by many people in the public. Therefore, all film stars are celebrities.
My concern is that it would lead to an infinite series of arguments and we would just end up talking in circles about nothing.
People in the public watch films. By watching films, one knows the actors. People in the public know the actors in films.
Do we eventually say that we are satisfied that the premise of a conclusion can stand on its own, or do we really just not continue this exercise infinitely because we would rather do something else with our time?