Material Causality and Extension

The concept of Material Causality, previously introduced, connotes immanent dynamic increase.  Now, insofar as 'extension' signifies a given, fixed multiplicity, e. g. three-dimensional Space, it does not exemplify Material Causality.  But, insofar as 'extension' is used as a participle, signifying an immanent development, it does exemplify Material Causality.  Thus, Descartes' concept of Extension, the dominant one in Modern Philosophy, connoting given, fixed three-dimensionality, does not exemplify Material Causality.  However, Spinoza's concept of Extension, an Attribute of immanent, dynamic Substance, perhaps a descendent of Plotinus' concept of Emanation, might exemplify Material Causality, though Spinoza does not elaborate on his use of the term sufficiently to confirm that divergence from the Cartesian concept.  However, whether or not he explicitly intends it as such, his concept of Modification does exemplify Material Causality.  For, his Modes are the products of Modification, and a specific human is the example of a Mode that is most important in his doctrine.  But, a specific human is a product of procreation, which, as has been previously discussed, is an instance of Material Causality.  Thus, his concept of Modification does exemplify Material Causality, which he misses not because the concept of Material Causality is unknown to him, but because, he glosses Variation as Individuation.  That is, he does not recognize that procreation is a process of a varying of the species, not merely a process of producing a new individual member that is independent of any other such process, which is what the concept Individuation connotes.  Likewise, therefore, insofar as Extension is an immanent dynamic Modification of the given, it, too, exemplifies Material Causality, thereby calling into question Spinoza's apparent exclusive commitment to Efficient Causality.