What is the author's tone in The Story of My Life by Helen Keller?

Although Keller occasionally lapses into emotional passages, her writing tone is generally formal. It is reminiscent of the lofty language of Greek writers and also of the similes and tones of biblical text. Toward the end of chapter two, for example, she writes, "Thus it is when we walk in the valley of twofold solitude we know little of the tender affections that grow out of endearing words and actions and companionship."