Sociology of ideas

This review article/interview plugging a book by Neil Gross that deals with Richard Rorty’s intellectual journey is noteworthy because the writer of this book refers to the sociology of ideas (SI) as superseding the sociology of knowledge (SK):

The old sociology of knowledge may have been terribly reductive — ideas are an expression of class interests or reflective of dominant cultural tendencies, etc etc — but the sociology of ideas today offers much more fine-grained theoretical tools.

This may well be but I’d be very interested to find out what distinguishes SI from SK and find out exactly what these finer-grained tools are.