B has no impact on the validity of the conclusion. Even if rubber was used for other purposes from 1000 to 1518, a year before Cortez's observation, it does not tell us anything about when the game must have originated.
Ryan-MahabirJuly 26, 2019
Understood, thank you.
SalvatoreJune 9, 2022
How come the negation of "The game had been played since its inception with a rubber ball" is "not necessarily played" instead of just "not played."
To be more clear, why is it #1 and not #2?
1. The game had not necessarily been played since its inception with a rubber ball.
2. The game had not been played since its inception with a rubber ball.
Emil-KunkinJune 10, 2022
Hi Salvatore,
I generally like to go with the weakest possible negation, and the #1 feels like the weaker statement. If we think that the game had not been played with a rubber ball since its inception, that would imply that from the time it was invented until Cortez showed up, it was not played with a rubber ball, and then everyone suddenly decided to start using rubber. Your #1 allows for much more flexibility.
We are negating a statement that equates to an "always." We do not have to assume the negation of always is never (which is your #2), but rather we could simply say "not always" which is your number 1.
