These sermons aren't actually authentic works of St. Thomas Aquinas, as claimed. Mark-Robin Hoogland, C.P. writes in Thomas Aquinas: The Academic Sermons (CUA Press, 2010) that "Note that none of the sermons in the collection Sermones dominicales et Sermones festivi (schemes or summaries of sermons, translated into English by John M. Ashley in London in 1873 and reissued in Washington in 1996) attributed to Thomas is his" (3 n. 1). That said, I imagine they're a pretty good sample of what preaching looked like in Thomas's day and age.