We all wonder about those long lifespans recorded at the beginning of Genesis. For example, we are told that Adam lived 930 years, that Shet lived 912 years, and that Metushelach lived 969 years. How have Jewish sources understood these numbers over the centuries?
The first Jewish source to address this issue was Josephus (late first century). Here is his statement in Antiquities, book I:
“Nor let the reader, comparing the life of the ancients with our own and the brevity of its years, imagine that what is recorded of them is false…For, in the first place, they were beloved of God and the creatures of God Himself; their diet, too, was more conducive to longevity: it was then natural that they should live so long. Again, alike for their merits and to promote the utility of their discoveries in astronomy and geometry, God would accord them a longer life…”
Now I will survey the views of our Geonim and Rishonim.
R. Saadiah Gaon (10th cent.) discusses this issue in his introduction to Tehillim. He writes that the longevity of these early generations was part of God’s plan for the rapid proliferation of mankind on the earth. The longer people lived, the more children they could have. It would seem that he believed that everyone in those early generations lived a long lifespan.
R. Yehudah Ha-Levi (12th cent.) discusses the issue in the Kuzari (sec. 95). He believes that it was only the individuals listed who lived long. Each of the individuals listed was the heart and essence of his generation and was physically and spiritually perfect. The Divine Flow was transmitted from one generation to another through these exceptional individuals.
Rambam, in a famous passage in the “Guide to the Perplexed” (II, chap. 47) writes: “I say that only the persons named lived so long, whilst other people enjoyed the ordinary length of life. The men named were exceptions, either in consequence of different causes, as e.g., their food or mode of living, or by way of miracle.”
Ramban (comm. to Gen. 5:4) quotes Rambam’s view and then disagrees, calling Rambam’s words “divrei ruach.” Ramban writes that the individuals with long lifespans named in the Bible were not exceptional in their lifespans. Rather, the entire world had long lifespans before the Flood. But after the Flood, the world atmosphere changed and this caused the gradual reduction in lifespans.
Most of the Rishonim who discussed the issue thereafter followed the approach of either the Rambam or the Ramban. Either way, they were taking the Genesis lifespan numbers literally. (An underlying factor that motivated Rishonim to accept the Genesis lifespan numbers literally was that the count from creation was calculated based on these numbers.)
Josephus had mentioned that one of the reasons that God allowed their longevity was to promote the utility of their discoveries in astronomy and geometry. This idea of longevity to enable the acquisition of knowledge and make discoveries (and write them to be passed down) is also included in several of our Rishonim. See, e.g., the commentary of the Radak to Gen. 5:4 and of the Ralbag to Gen. chap. 5 (p. 136), and the Rashbatz, Magen Avot, comm. to Avot 5:21.
Rashbatz also mentions the idea that the early generations were close in time to Adam and Adam was not born from a “tipah seruchah” like the rest of us, but was made by God from the earth. Those early generations inherited his superior bodily constitution.
Another idea found in some of our Rishonim is that those early individuals did not chase after “ta’avat ha-guf,” which reduces the lifespan. See, e.g., the commentary of the Radak to Gen. 5:4.
But there were some Rishonim who were unwilling to take the Genesis lifespan numbers literally.
The earliest such source that we know of was R. Moses Ibn Tibbon (late 13th cent). He suggests that the years given for people’s lives were actually the years of “malkhutam ve-nimuseihim,” i.e., the dynasties and/or customs that they established.
Another figure who took such an approach was R. Levi ben Hayyim (early 14th cent.). First he mentions several of the possibilities to explain the longevity, e.g., good and simple food and “marrying late” (!). But then he concludes that in his opinion the names mentioned were just roshei avot. In other words, the number of years given for each individual reflects the total of the years of the several generations of individuals named for that first individual.
R. Nissim of Marseilles (early 14th century) was another who did not take the numbers literally. He took the same approach as R. Moses Ibn Tibbon. The numbers did not indicate the lifespan of the specific individuals named. Rather, it included the total years of the descendants who followed his customs and lifestyle.
The most interesting approach I saw was that of R. Eleazar Ashkenazi ben Nathan ha-Bavli (14th century), in his work Tzafnat Paneach, pp. 29-30. First, R. Eleazar refers to the view that perhaps the individual numbers were not to be taken literally, and points to other statements in the Torah that were not meant to be taken literally, e.g., 1) the Land of Israel was “flowing with milk and honey,” and 2) the cities in Canaan were “fortified up to the Heaven.”
But then R. Eleazar suggests the following creative approach. In listing these individual numbers, the Torah was merely recording the legends about these figures, even though they were not accurate. The important thing was to provide data from which the total years from Creation to Matan Torah could be derived, so that the people would be able to know the length of time between these two periods. Even though the numbers for the individual lifespans were not accurate, the Torah made sure that the total that would be arrived at would be accurate. (In contrast, when it came to events from Avraham and forward, the Torah was careful to preserve a more accurate accounting.)
In modern times, one Orthodox scientist who has written much on this topic is Prof. Natan Aviezer of Bar-Ilan Univ. He discusses this topic in a post at their parshah site for Noach, 1998. There he explains that modern science has figured out that aging is largely caused by genes, and not by a wearing out of our bodies. He then suggests that when God stated at Gen. 6:3 that man would be limited to 120 years, this was when God first introduced the gene for aging into the human gene pool.
If you have not found any of the above answers satisfying, I have some good news. R. Saadiah Gaon writes (Emunot Ve-Deot, ch. 7) that in the era of the redemption the human lifespan will be approximately 500 years. Presumably, at that time we won’t be bothered by those long lifespans in Genesis anymore!
I would like to acknowledge that most of the material above came from an article by Prof. D. Lasker of Ben-Gurion Univ. in Diné Yisrael, vol. 26-27 (2009-10).
Mitchell First aspires to longevity and hopes his children can tolerate him for that long.