The Semi-Arian position — associated with the Homoiousian party at the councils of the 340s-360s — held that the Son is homoiousios (‘of similar substance’) rather than homoousios (‘of the same substance’) as the Father. The difference is a single iota (ι) in Greek — giving rise to the dismissive phrase ‘iota of difference.’ Jerome complained that ‘the world woke up and found itself Arian’ after the Council of Sirmium (357 AD). The Semi-Arians were a broad middle party who accepted the Son’s divine dignity but were uncomfortable with the Nicene formula’s non-scriptural philosophical terminology. Emperor Constantius II promoted Semi-Arianism as a compromise. Ultimately the Semi-Arians were absorbed into the Nicene coalition under pressure from Athanasius and Basil of Caesarea, who persuaded them that homoousios need not imply Modalism.