Orchidsandfractals
I always thought that the Sabbats were to honor the Goddess, and the God. Beltaine is for the God, Isomblek(Not prononucning it right, but the one in Feb.) is to honor the Goddess, Samhain is to honor the God, and the other one, Lugohasa is to honor the Goddess. However, I'm not a Wiccan, and this is based off what my neopagan raising told me?
Esbats are more about the Goddess and the Sabbats are more related to the God's journey through the Wheel of the Year.
Lughnasadh is not in honor of the Goddess. Lugh was a Celtic God, and that particular Sabbat is named after him.