Sophie began teaching herself mathematics and other topics using the books in her father's library. But her parents felt that her interest was inappropriate for a female (the common belief of the middle-class in the 19th century), and they did all they could to discourage her. She began studying at night to escape them, but they went to such measures as taking away her clothes once she was in bed and depriving her of heat and light to make her stay in her bed at night instead of studying. However, their efforts failed. She would wrap herself in quilts and use candles she had hidden in order to study at night. Finally. and they realized that Sophie's passion for mathematics was "incurable," and they let her learn. Thus, Sophie spent the years of the Reign of Terror studying differential calculus without the aid of a tutor. She was self-taught. 