Having only the a very cursory knowledge of Structuralism, there does appear to be some points of coincidence:
Structuralism:
- Individual elements of culture must be placed within a System/Structure.
- The individual elements of culture must be understood by their inter-relationships within this System, and not by their individual identity, that is their identity is supressed.
and compare this with Category Theory:
- Individual objects of mathematical interest must be placed with a Category.
- Though these individual objects have their own character, this knowledge is supressed, and only their relationships (called morphisms) have import.
There seems to me a clear correspondance here. Of course, it could mean that both paradigms evolved independently from some prior philosophy. I'm thinking of Leibniz rather than Kant, from whom Saunders MacLane, one of the two cofounders of Category Theory, purloined the word 'Category' for his own uses. He also studied at Gottingen, which from my limited knowledge of German philosophical history, was a centre of philosophy, presumably due to Kant.
Some more evidence from Structuralism, by Sturrock:
'What is a structure, then, for Husserl, and 'in general'? The broadest definition is that a structure is an abstract model of organisation including a set of elements and the law of their composition...What stands out in a structure is that the relationships between the elements are more important than the intrinsic qualities of each element'.
and the definition of a category can be further elaborated as:
3.Morphisms between objects (i.e. the relationship) follow a law of composition.