Play it safe or play it rational (Chulin 48b)

So here's a question: you find a needle in the lung of an animal. Is it the animal (and lung) kosher or not?

The issue at hand is whether the needle punctured the lung. If it did, the lung is considered traif and thus the animal is not kosher. If it didn't the animal is fine.

What's interesting about this question is that Rabbis Yochanan, Elazar and Chanina permit the animal for eating, while Shimon Ben Lakish, Mani bar Patish, and Shimon be Elyakim say it is traif. That's a pretty big (and even) split.

At the heart of the disagreement is how the needle got into the animal in the first place. There are really only two options. The animal could have swallowed it or aspirated it.

If the animal swallowed it, the needle would have had to have left it's digestive track, puncturing it's intestines (another way an animal become traif) then entered into the lungs by puncturing it from the outside. If the animal aspirated it, the needle would simply have gone down the wrong tube (if there is a right one for a needle!) and the presumption is that it would not have made any holes.

At the root of this debate is whether we privilege rational explanations or halachic certainty. Rationally, it makes much more sense that the needle was aspirated than that it left a cows intestines and found it's way into a lung. That's why Yochanan and his group render the animal kosher. However, Shimon ben Lakish and his group privilege something entirely different. As far-fetched at their scenario may be there is a chance it could have happened. Since the only thing you can be sure about in this situation is that you are not eating non-kosher meat if you prohibit the animal they deem the organ traif and play it safe.

Jewish law is a dance between what is rational and what is safe. Sometimes these two ideals line up. Sometimes, as it does in today's daf, they do not and you must decide which of these two values to privilege.

How to avoid a dishonest reputation (Chullin 44b)

A useful teaching in today's Daf:

If one adjudicated a case (concerning contested property) and ruled in favor of one party and against another, or he ruled an item impure or pure or the ruled it forbidden or permitted, and likewise if witnesses testified about the property all of these (the judges and witnesses) are allowed to buy the item [in which they played a role in permitting or invalidating]. However, the sages said, keep far away from unseemliness and from anything resembling it. 

Here the sages give sound advice. If I am a judge and I award someone lost property and then he turns around and sells it to me, doesn't that look fishy? Have I ruled in accordance with his claims because I knew he would sell it to me at a fair price?

The answer may be no, however just by raising the question I have planted in your mind the question of my honesty and integrity. We live in a world where those two values are so easily lost. The sages are right. If there is a change it might seem fishy, avoid any hint of it, even if it is a fair (and smart) purchase.