The Goddess Maat
Without this goddess the whole process of creation and constant renewal of life has no meaning, because she symbolized the laws of existence, justice, truth and order in the world - and the courts were his priests.
The natural cycle of life would have been impossible without her, which provided food and drinks Ra, his father, the god of the Sun: depictions in his head appears adorned with an ostrich feather, which became the symbol of truth, perhaps because symbolically connected to the third eye (see Hindu culture) that can see deep into the ultimate truth.