Said more precisely : As regards a given attributable formal content, we must in its definition, always mention a subject. If this mentioned subject is moreover a proper subject (that is a subject with a definite and explicitly formulated content), then the attributable content is coexistent with the subject, and thus, in a way, essential to this subject (in the sense of being a specific proprium). If the mentioned subject is not the proper subject (but just a subject), then the attribution of the formal content is per accidens.