Eiruvin 10a, b

Trying to better understand when it is permitted to carry in an alley on Shabbat, the rabbis delve deeper into questions about one particular scenario: when an alleyway looks from the inside to be opening onto a public domain, but from the outside, the walls of the alley extend into to that public space.  Their arguments include the required length of the alley walls as they protrude, the height of those walls, the width of the crossbeams, the placement of the side posts, and more, and more and more.

When I read these dapim, I seem to cling to the moments that shed light on the actual lives of these men and the society they describe.  What is said - and what is omitted - tells much about an entire world.  One of those moments is offered to us in 9a when Rabbi Yosef is confronted with one of his former rulings. He says that he "did not hear this halacha".  The note in Koren suggests that Rabbi Yosef was ill and did not remember having learned the halacha from his teacher, Rav.

Of course Rabbi Yosef had an amazing memory.  All of the rabbis that we read about had memories that I cannot fathom.  To present Rabbi Yosef's failing memory, therefore, is significant.  We are introduced to the Rabbi as a human being.  His student, Abaye, goes on to remind Rabbi Yosef just what he had taught Abaye in the past.  The end of the ruling concludes that we learn three things from the case in point: 
1) it is prohibited to carry in the area between side posts;
2) an alleyway must be at least four cubits;
3) a side post that can be seen from the alley but from inside the alley seems to extend to the public domain has the legal status of a side post.

What Rabbi Yosef had taught Abaye was important in understanding eiruvin.  It was memorable (to Abaye, at least), informative, authoritative, and longstanding.  When Abaye shares the forgotten halacha, Rabbi Yosef could have taken it as an insult.  However, pointing out the "facts" -- errors in logic or memory -- are commonplace in the Talmud.

In 10b, Abaye and Rav Dimi disagree about what they are disagreeing about.  A good number of sentences relate their attempts to understand exactly what the other is arguing, and whether those arguments are in fact contrary to each other.  

I believe that being compassionate and kind is an important ingredient in productive intellectual debate.  However, I wonder if we have somehow lost the ability to struggle with each other toward a shared understanding of our intentions.  We become defensive - proving that we are 'right' is more important than getting to a larger picture or understanding.  I would not suppose that these Rabbis, as great as they were, could teach us everything we need to know about compassionate debate.  However, today's daf reminds me that I can search for places to experience  open disagreement; argument that clarifies numerous differences for the sake of seeking a shared truth.