  The determinacy of the material particular is set against the non-determinacy of the Form. This determinacy of property is only one aspect of the difference. A second is the contingent way in which the particular has this determinate property. The material aspect is, in the case of particulars, partly responsible for the contingency of its property possession. Matter is a sufficient condition for contingency but not necessary, since souls are in many respects contingently what they are, e.g., desirous of money. (Matter is also a sufficient condition for complexity, though again not necessary, if souls, or Forms, can be complex.)