A Fragment on Government preface (1776). Bentham said that he derived this formula from either Joseph Priestley or Cesare Beccaria; Beccaria is the more likely. If Priestley was the source, then Bentham was paraphrasing him because the phrase is not found in Priestley's writings. See Beccaria 1; Hutcheson 1
Jeremy Bentham (1844). “Benthamiana: Or Select Extracts from the Works of Jeremy Bentham. With an Outline of His Opinions on the Principal Subjects Discussed in His Works”, p.95