Helvidius (sometimes Helvetius) was the author of a work written before 383 against the belief in the perpetual virginity of Mary. Helvidius maintained that the mention in the Gospels of the "sisters" and "brethren" of our Lord was proof that the Blessed Virgin had subsequent issue, and he supported his opinion by the writings of Tertullian and Victorinus. The outcome of his views was that virginity was ranked below matrimony.
St Jerome, in reply, wrote a treatise known under the title The Perpetual Virginity of Blessed Mary[1], where he vigorously takes the other side, and argues that the "sisters" and "brethren" spoken of, were either children of Joseph by a former marriage, or first cousins, children of the sister of the Virgin. When Jerome wrote this treatise both he and Helvidius were at Rome, and Damasus was Pope. The only contemporary notice preserved of Helvidius is contained in Jerome's treatise.