Black Robe
The black robe that Ruth Bader Ginsburg - and the rest of the Justices on the Supreme Court - wears is symbolic of the Court's importance, stature, and uniqueness.
Cancer
The cancer that Ruth Bader Ginsburg dealt with on more than one occasion is symbolic of the tremendous struggle she had to go through and her perseverance in life despite difficult circumstances.
Struggle
A common motif in I Know This to Be True is struggle, specifically Ruth Bader Ginsburg's health struggles, her struggles to overcome bias, and her struggle to do the best work she could do.
Feminism
A common motif in the book is feminism, which Ruth Bader Ginsburg was a proponent of (and something that she fairly frequently preached about).
The Supreme Court
The Supreme Court itself is symbolic of the United States' uniqueness, rule and order, and opportunity.
