 It is a term predicated homonymously (mahmul mushtarak) of its referents. Many things exist that are qualitatively and quantitatively distinct but all carry the term ‘existence’ (Mulla Sadra 2001–5, I: 40). Of course, the real question is whether existence is merely homonymous in the way in which ‘pole’ is. Existence constitutes a special case of homonymy that he calls tashkik, a term already used by Avicenna to render the tertium quid of the ancients. He argues that the key properties of tashkik are difference between existents ‘by precedence and priority’ (al-awlawiyya wa-l-awwaliyya), and ‘by being more prior and more intense’ (al-aqdamiyya wa-l-ashaddiyya) (Mulla Sadra 2001–5, I: 42–3). This is posed directly in response to Avicenna’s denial that substances can be more intense or that they can be distinguished by a non-accidental property that they possess. It is, therefore, in this sense that existence is both the source of commonality and of distinction between existing things because unlike the Peripatetic tradition, he is insistent that existence is the principle of individuation (tashakhkhus) of a thing other than its essence.