True. The argument wasn't logically sound. Although, to be clear, I was not saying that there was no possibility as you're now claiming. And I'm not sure how your statement about the Black Death supports your argument. As we all know, the Black Death passed. It continues to pop up from time to time, but that's true of almost any disease.
Perhaps a more convincing statistic would be that Ebola does not have a 100% mortality rate. This would suggest that, technically, it will pass since there will be survivors. Again, I think people are more concerned about how quickly that will happen and if/when it will resurface, which it probably will.
To be clear, I don't believe this currently outbreak of Ebola is going to infect everyone, and I do believe it will pass. I'm just saying that there could very well be a pandemic some time in the future that does take a massive toll on the human population. The reason I say that is because it has happened many times in the past, even within the 20th century.
Perhaps a more convincing statistic would be that Ebola does not have a 100% mortality rate. This would suggest that, technically, it will pass since there will be survivors. Again, I think people are more concerned about how quickly that will happen and if/when it will resurface, which it probably will.