A comparative analysis of Ep. 361 and Eun. 1.19 in terms of language and ideas will offer a renewed confirmation (on internal grounds) of Basil of Caesarea’s authorship of Ep. 361 and a new perspective on Basil’s relationship with the Homoiousians. In addition, the article will also retrace the steps and revisit the purpose of Basil’s argument. Thus we discover in the early Basil an author simultaneously receptive to both Homoiousian and pro-Nicene visions, but leaning towards an improved Homoiousian solution. The article further investigates Basil’s vision of ousia in Ep. 361 and finds that—unlike in his later, mature, period—the early Basil shares with the Homoiousians and Eusebius of Caesarea two doctrinal elements, namely the understanding of ousia as individual substance and an associated theology of “likeness”. He inherits this view from a tradition originating in the third century, which received its official confirmation at the council of Antioch in 268. This vision is also present in the first part of Basil’s Contra Eunomium. Instead of considering Basil as a Homoiousian, one may see him, together with Eusebius and the Homoiousians, as a representative of the Antiochene legacy.