The first blessing in the middle section of Shemone Esray (blessings 4-16) is Attah Chonain. In this blessing, we ask for wisdom and understanding. The Shulchan Aruch mentions that this is the first blessing in the middle section because the ability to think is the thing that separates a human from an animal. If we did not have the ability to think, we would not be able to pray. Therefore, this is the first blessing.