Aquinas argues against this position in Disputed Questions on the Soul (Quaestiones disputatae de Anima), asserting that, while the passive intellect is one specifically, numerically it is many, as each individual person has their own passive intellect.
In his work "Disputed Questions on the Soul," Aquinas refutes the idea by stating that although the passive intellect is singular in its essence, it exists in multiple forms because every individual has their own unique passive intellect.