I assume Howe is suggesting that ED is reacting to “the idea that our visible world is a whim and might be dissolved at any time” and that people of her day were willing to show “obedience to a stern and sovereign Absence” which “forged a fanatical energy necessary for survival”. The “obedience to a higher purpose” is plain and simple; ED disagrees, though she does still seem to believe in some sort of spirit.