Me'ila 20: How Do We Define a Vegetarian?

Today's daf explores what is included in a neder, vow, to not eat meat.  The Gemara shares a baraita teaching that fish and grasshoppers would not be included, though they are kosher.  All other meat including poultry and all parts of animals would be part of the vow.  

Rabbi Shimon ben Gamliel says that ordinary meat would be included in the vow, but poultry, fish, grasshoppers, livers, hearts and other innards would be outside of the vow.  Generally, internal organs are not considered to be the most valuable parts of animals to consume.  Steinsaltz teaches us that only the poorest (or ill) Jews partook in eating these meats in the past.

Rabbi Shimon ben Gamliel says that "kravayim, innards, are not considered to be meat and one who eats them is not a person."  Commentators often remove this line from the Gemara.  Rashi explains that Rabbi Shimon means that people who eat these parts of the animals include them in their vows.