Some of the earliest possible references to foot binding appear around 1100, when a couple of poems seemed to allude to the practice. Soon after 1148, in the earliest extant discourse on the practice of foot binding, scholar wrote that a bound foot should be arch shaped and small. He observed that "women's footbinding began in recent times; it was not mentioned in any books from previous eras." In the 13th century, scholar wrote the first known criticism of the practice: "Little girls not yet four or five years old, who have done nothing wrong, nevertheless are made to suffer unlimited pain to bind feet small. I do not know what use this is."