I had an "I'm stupid" a-ha moment a week or so ago in relation to the use of "brothers and sisters" to translate the Greek word "brothers" in the New Testament.
Ever since the TNIV, I've been explaining to others that versions like the NRSV, the NLT, the TNIV, and now the NIV2011 only used "brothers and sisters" when they thought Paul already included them. So when Paul tells the brothers to flee sexual immorality in 1 Thessalonians 4, he was surely not letting the sisters in the congregation off the hook.
That's all true, but I (stupidly) just caught on that this is not just a dynamic equivalent translation. It actually can be justified grammatically. Up until recent days, when you were speaking or writing to a mixed group of people in a gendered language, the convention has been to go with the masculine plural ending. This has previously been true, for example, in Spanish. If you were speaking to a group of men and women, you would normally say "amigos" and use the masculine plural ending. You have to pick a gender, so up until recent times you would have naturally used the masculine for a mixed group.
It hit me like a ton of bricks. It would be normal for a Greek speaker to address a mixed group of men and women with "brothers," fully including the women in the masculine plural ending. The implication is that in an age where it has become appropriate to be explicit about references to women in one's language, the best translation of "brothers" actually becomes "brothers and sisters." This is not just because they are implied in Paul's meaning. They are implied grammatically as well.
So I repent of my stupidity. Brothers and sisters actually becomes a more accurate translation, and versions like the ESV actually turn out to be inferior translations in this regard.