Like every other writer from Antiquity onward, Bernard was acquainted with the theme of the ‘weaker sex’. He did not overuse it, and in the only three cases where he did use it, he retained the original meaning – a lesser physical strength, somewhat akin to the weaker strength of youth as compared with that of adulthood: he says so clearly in a letter in which he congratulates a young nun on overcoming the double weakness of ‘a fragile sex and age’. The formula he used comes from the liturgy, where it is used in praise of women who show courage in the face of martyrdom and in other circumstances. Elsewhere, in addressing men, Bernard used the comparative and spoke of the ‘more fragile sex’, or the ‘weaker sex’. Only once, with the intention of humiliating prelates who dressed like women, did he mention the sex and ‘order’ or social category which is, by comparison, ‘baser’. But to speak like that in those times was the accepted thing.
Jean Leclercq, Women and Saint Bernard of Clairvaux (1989)