Q&A: Gittin 28
Gittin 28
Question
Hello Rabbi,
In the Talmudic passage about the presumption that a person is alive, the Gemara says, “once he has passed beyond it, he has passed beyond it,” and in Rashi on the words “he has passed beyond it” — “and he is not like other people, to be close to death; but someone who is eighty-one or older up to ninety is close to death.” This is of course completely implausible. Is there some way to try to understand the Gemara differently, maybe with another interpretation???
Answer
Why is it implausible? It really isn’t implausible at all. One can discuss at what age this is true, but there are many mechanisms like this. For example, the life expectancy of people who have passed age 40 is around 90. The stages of death are not distributed uniformly across the age axis. Again, that doesn’t mean the Gemara is specifically correct about those particular ages, but the mechanism exists.
Discussion on Answer
Yoni,
Take it backward. The general life expectancy of a person is X. If you calculate it only for those who have passed age two, it will be higher, because crib death is no longer relevant for them. If you calculate it only for people after army discharge, risk factors connected to war will also disappear.
At some stage, of course, factors of old-age illness enter the picture, but the principle that an older segment of the population can have a higher life expectancy is not implausible at all.
It’s obvious that the life expectancy of a 70-year-old is higher than that of a 30-year-old, and that’s what you wrote. But the risk of dying (and that’s what’s relevant to the presumption that someone is alive) is higher the older a person gets relative to someone younger, maybe with an exception for very small babies.
Risk of dying is mathematically derived from life expectancy.
If you calculate the general life expectancy of human beings, it will be X. If you calculate the life expectancy of all human beings except ages 0–2, it will be Y, where Y is greater than X. That implies that the probability that a two-year-old will die tomorrow is lower than the probability that this will happen to a six-month-old.
I don’t think this is true only in those age ranges. I don’t know the data, but I would guess it’s true up to the area where old-age illnesses begin. In any case, the numbers are not the discussion here, but the principle.
I don’t understand what there is to discuss. A. Are you arguing with the basic assumption that the older a person gets, the greater the risk of death? So true, that assumption probably won’t hold when comparing younger people, for example a group of 20-year-olds to a group of 30-year-olds. But if you sample a group of 60-year-olds and a group of 80-year-olds over a period of time, you will certainly find that among the 60-year-olds fewer people died during that period. Which shows that their presumption of being alive is stronger, and that is what is relevant for determining who has a stronger presumption of life. And about that I want an answer explaining the Gemara.
B. It’s also a bit unclear what you mean by life expectancy. It is usually defined as the average lifespan at birth, and it is indeed derived from the risk of dying. (Not as you wrote, that risk is mathematically derived from life expectancy, but the other way around.) In any case, when we speak about the life expectancy of a person in midlife, the question is: how much longer does he have left to live on average? And here it is obvious that the older he is, the lower the numerical answer will be, as I wrote in section A.
I’d like to ask again: who is at greater risk of dying, the 80-year-old or the 90-year-old? I’m mentioning specifically these ages because this is the case in the Gemara and Rashi in Gittin 24. It’s obvious that the 90-year-old is at greater risk, so I’m asking how the Gemara can be understood when it claims the opposite because of the reasoning, “once he has passed beyond it, he has passed beyond it.”
Please, could the Rabbi respond to me?
A. I do indeed disagree with the assumption that the older one gets, the greater the chance of dying. That is true in some ranges, and in others it isn’t. You also agree to that, except that you claim that the specific numbers presented by the Gemara are not correct. I’m not arguing about that, because I don’t know. Maybe you’re right, and the situation in their time was different. Or maybe in their period there were illnesses that struck only 80-year-olds, and someone who made it past 90 was on average a robust person who held out until 120. I don’t know, and I assume you don’t either.
B. Life expectancy is a statistical estimate over expected lifespan. You can calculate it at birth, and you can calculate it at another age. It’s simply a matter of statistical inference from existing data.
Thank you very much, I understand.
P.S. I only just now realized that “Avi” is actually the Rabbi.
That’s not me, but since he answered you, I didn’t respond. That’s also why I deleted the questions you posted separately. There’s no point in duplicating discussions in order to force me to answer.
I’m not the Rabbi. I’m not worthy. 🙂
If you are not the Rabbi, and assuming you also weren’t sent to answer, then as a matter of manners and common decency it isn’t proper to jump in and answer when the questioner is waiting specifically for a response from the Rabbi. Unless the Rabbi had already responded.
Maybe you were trained by Hannah of Babylon, but here on the site the rules of etiquette are different. Anyone who wants to may respond to any question. Besides, I had already responded.
I didn’t understand. It’s obvious that people in their 80s are less likely to die than people in their 90s, and that’s what’s relevant to the question of the presumption that someone is alive. It’s completely obvious that if I take a sample of people in their 80s and people in their 90s and check after some period of time (say 5 years), then among the people in their 90s there will be more people who have passed away.