by Rabbi Yaakov Jaffe

Scientists engage in an ever-lasting pursuit to understand the world that we live in, to provide rules and explanations for the unknown, and to pierce the veil between us and the mysteries of creation, such that even the most complex, distant, or tiny system is as accessible to us as the palm of our hands.

Sometimes, however, scientists reach the limits of human understanding – such that they cannot identify for certain where exactly a particular electron might be found at any given moment, cannot visually observe the existence of a far-flung planet orbiting a distant star, cannot explain the exact relationship between genetic and environmental factors in the development of schizophrenia, or the way in which particular genes are turned on or off in utero as a result of genetic or hormonal circumstances in the womb.

When faced with the unknown, or with the unknowable, scientists take three different approaches as to how to capture the reality of creation as best they can, without absolute certainty.

One approach is to speak in terms of probability: we don’t know exactly where an electron might be, but instead we can talk about the probability where we might find it.

A second approach is to use simulations or models to discuss what capture what we don’t know: we haven’t observed a planet in a particular place yet, but our simulation of gravitational impacts of orbits in a particular solar system demonstrates where planets might be. 1Of course, some might argue that mathematically, any simulation is really just a complex probabilistic system carried out using a computer program, and thus in essence there is no difference between the first two approaches.  However, on a human, experiential level, they operate slightly differently.

A third approach, this more common in medicine or engineering than in the basic sciences, might confess or admit that we don’t really understand how a complex system works, but that we still have to move forward with an intervention that makes some assumptions about the system which we know may not be accurate but which work for us to move forward. 2These approaches differ on an epistemological level – how we come to know and understand things – and not an ontological level – the nature of the various things, themselves.

In parallel, Jewish Law also sometimes reaches situations where it confronts an unknown, and interestingly at times uses the same three different approaches.  Consider the following, somewhat mundane, scenario of the “unknown.”  Two cows stand side-by-side, one Kosher (as it was slaughtered humanely in accordance with Jewish law), one non-Kosher (as it was electrocuted, instead, rendering it non-Kosher).  From these two cows, come three nearly identical slices of meat: two from the Kosher cow, and one non-Kosher.  Then, the three slices of meat are mixed – leaving an unknown: which slice of meat is kosher?  Which is non-kosher?

Rosh (Chullin 7:37) famously took the third approach in this case.  We confess we do not know, and will never be able to know which was Kosher and which wasn’t – and so we move forward making assumptions that we know are not accurate.  A Jew may eat all three pieces of meat and all three are treated as Kosher.   Rather than be paralyzed by an inability to know completely, we chart a past moving forward that works, even if we know it isn’t 100% true. 3The rationale behind this approach is that once the three become a mixture, a mixture becomes defined by its majority, which is Kosher – so our path forward is to treat them all as kosher, even if we know that isn’t the nature of the three pieces.

His teacher, Meir of Rottenberg (cited by Heller, loc cit) took the second approach, arguing that a simulation was the best way to move forward.  One piece of meat is removed and given to a person who is not required to eat Kosher, simulating the original reality where one piece is non-Kosher and two are Kosher.  This simulation captures the unknown within the mixture, though it is not a perfect representation of the real truth of the scenario. 4Some argue that Meir of Rottenberg fundamentally agreed with the calculation in the previous note, and merely required the simulation in an effort to assuage the unsightliness of choosing a path forward which was surely incorrect.  Meir’s simulation had at least a chance of being correct, so it was chosen, even though mathematically the chances of it being correct are so small it couldn’t stand on its own without the ideas in the previous note.

Still others take the first approach (see Moshe of Coucy), that one needs to approach the model using probability.  If one person eats all three pieces of meat, the probability of him or her having eaten non-Kosher is 100%, so therefore one person cannot eat all three.  Multiple people must eat the different pieces of meat, because by doing so, the probability of each person having eaten non-kosher lowers for each one to the point of acceptability. The three pieces of meat is another example of the famous let’s make a deal probability problem.  5The first meat has a 33% of being non-kosher, and if we assume that the first was non-kosher, the second has a 50% chance of being non-kosher; although after the two pieces have been eaten the person has a retroactive 66% chance of having eaten non-kosher.   Exactly at which probability we draw the line and permit the consumption of the meat, and also how we even think about the problem is beyond the scope of this brief analysis.  Further complicating the problem is the question debated for centuries whether this analysis is predicated upon a 2/3rd kosher majority, or even a 51% majority would suffice.

Human response to the unknown often charts and takes similar forms – whether an unknown in the world of science, or in the world of religion.

(This post is part of Sinai and Synapses’ project Scientists in Synagogues, a grass-roots program to offer Jews opportunities to explore the most interesting and pressing questions surrounding Judaism and science. This post is from Maimonides Minyan, a Modern Orthodox kehilla in Brookline, Massachusetts. It is adapted from a sermon delivered by Rabbi Jaffe).

References   [ + ]

1. Of course, some might argue that mathematically, any simulation is really just a complex probabilistic system carried out using a computer program, and thus in essence there is no difference between the first two approaches.  However, on a human, experiential level, they operate slightly differently.
2. These approaches differ on an epistemological level – how we come to know and understand things – and not an ontological level – the nature of the various things, themselves.
3. The rationale behind this approach is that once the three become a mixture, a mixture becomes defined by its majority, which is Kosher – so our path forward is to treat them all as kosher, even if we know that isn’t the nature of the three pieces.
4. Some argue that Meir of Rottenberg fundamentally agreed with the calculation in the previous note, and merely required the simulation in an effort to assuage the unsightliness of choosing a path forward which was surely incorrect.  Meir’s simulation had at least a chance of being correct, so it was chosen, even though mathematically the chances of it being correct are so small it couldn’t stand on its own without the ideas in the previous note.
5. The first meat has a 33% of being non-kosher, and if we assume that the first was non-kosher, the second has a 50% chance of being non-kosher; although after the two pieces have been eaten the person has a retroactive 66% chance of having eaten non-kosher.   Exactly at which probability we draw the line and permit the consumption of the meat, and also how we even think about the problem is beyond the scope of this brief analysis.  Further complicating the problem is the question debated for centuries whether this analysis is predicated upon a 2/3rd kosher majority, or even a 51% majority would suffice.