The Mirror (Symbol)
In the beginning of the book, when Christine meets the three Ladies for the first time, she is given a mirror to look into. The reason behind this is that one of the Ladies claimed that Christine was not able to see herself properly because she was influenced by what men thought about her and her view was not hers but actually a male view imposed on her. Thus, the mirror becomes a symbol of truth, as only through looking at herself (and by extension, other women) can Christine come to recognize women's worth.
The City (Allegory)
The Book of the City of Ladies is an allegorical work, and the city that Christine constructs is itself an allegory for the collective strength, virtue, and feats of women past and present. Christine de Pizan constructs the city as an idealistic, almost utopian place where women can be protected from the criticisms and advances of men; the city is held together by the cataloguing of women who have demonstrated these qualities over time.
The Pen (Symbol)
At the beginning of the book, Lady Reason leads Christine de Pizan to the place where the city will be built. This place is called the Field of Letters, and Lady Reason instructs Christine to start building the city using her pen. The references to letters, reading, and writing help turn Christine's pen into the symbolic tool for erecting the city. That is, the City of Ladies is constructed through Christine's engagement with intellectual history (notably, something Mathéolus argues is off limits to women).
The Ladies (Allegory)
In what was a popular literary trope of the medieval period, The Book of the City of Ladies uses allegorical representations of the virtues Reason, Rectitude, and Justice to make its broader arguments. These virtues appear to Christine as Ladies, all of whom wish to inform Christine of women past and present who have acted with superb moral and intellectual character. In using allegory this way, de Pizan suggests that the virtuous position to hold is one that celebrates and honors women rather than criticizes them.
Virgin Mary (Symbol)
The Virgin Mary is both a symbol and a very real inspiration for Christine and the Ladies as they construct the City. When it is announced that the Queen of Heaven will be the ruler of the City, Mary becomes a symbol of the ideal woman: strong, virtuous, and having a profound effect on the history of Christianity.
