Eiruvin 39a, b

Today's daf includes a conversation about something I've observed all of my life without knowing the debate at its source.  In the diaspora, we observe two days of Rosh HaShana and two Festival days rather than the one-day observance that was prescribed by Torah law.  I have always believed that this is because communication of when the actual day started in Jerusalem was unreliable.  Thus we observe two days to ensure that we celebrate over the proper day.

In daf 39 we are introduced another idea.  Some of the rabbis suggest that both days should be treated as one long day of observance, even though the two-day custom is 'only' rabbinical law.  This applies to the conversation at hand: if we place an eiruv by foot or with bread at the start of the two day Festival, the rabbis must determine whether or not we require another eiruv for the second day.

It is amazing to practice the same rituals as these ancient scholars.  Reading Talmud does highlight how ancient the customs are.  I don't usually think twice about observing a second day of Rosh HaShana.  But reading the considerations that brought about that ritual somehow removes the normalcy of the ritual.  So I suddenly feel as though I'm being hypocritical, practicing something that I just can't 'believe'.  However, I do not plan to change my practice of halacha... not right now, anyhow, in either direction.