The claim of modern medicine being responsible for longer lifespans is of course a statistical claim, i.e. the average/net effect. Thus your second assertion does not follow logically. Though it is an interesting point.

Diseases, both now and in the past, do not have 100% mortality rates. If you followed the ebola outbreak you'd have heard stories of survivors are quite common. The same is true with measles, the common cold, lung infections, etc. When we find a cure for a disease the lifespan statistic increases. This is because those people who would have died survive instead, NOT because infected people avoid long-term collateral damage that would have taken a few years of their 'original' lifespan. At least that is the current predominant view of things.

The claim of modern medicine being responsible for longer lifespans is of course a statistical claim, i.e. the average/net effect. Thus your second assertion does not follow logically. Though it is an interesting point.

Diseases, both now and in the past, do not have 100% mortality rates. If you followed the ebola outbreak you'd have heard stories of survivors are quite common. The same is true with measles, the common cold, lung infections, etc. When we find a cure for a disease the lifespan statistic increases. This is because those people who would have died survive instead, NOT because infected people avoid long-term collateral damage that would have taken a few years of their 'original' lifespan. At least that is the current predominant view of things.

Consider the following:

• Diabetes decreases individual lifespan, ergo the average lifespan also decreases if enough people get diabetes.
• The common cold does not decrease individual lifespan, yet it still contributes to a lower average lifespan because it may be fatal in weak individuals.

So we could say (almost) every illness shortens the average lifespan, but not every illness shortens individual lifespan.