What basis could there be for an 18th century Christian to say that "Gnostics were the Antinomians of their day"?

I read that claim in an article written by A.M. Toplady (reproduced in a 2020 Christian magazine.) Toplady (1740-1778) did not go on to give his reasons for that claim, apart from adding, "An Antinomian looks to be justified by his works." Toplady is best known for hymns, such as *Rock of Ages* and verse 2 shows his view on the matter of works: "Not the labour of my hands can fulfil thy law's demands. Could my zeal no respite know, could my tears forever flow, all for sin could not atone. Thou must save, and thou alone." His article, however, was dealing with text from the Bible letter of James, written before the end of the first century. Therefore, ***I'm asking this question to those who know about ancient Gnosticism circa the end of the first century, and who also know about Antinomianism.*** Please bear in mind that I'm *not* looking for any opinions about Gnosticism and/or Antinomianism, whether they are good, bad or indifferent religious beliefs. **I'm simply wanting to know why Toplady could have made the claim, "Gnostics were the Antinomians of their day."** What basis might he have had for that?