Following Kripke ([1980]) and Putnam ([1973], [1975]), the received view of chemical kinds has been a microstructuralist one. To be a microstructuralist about chemical kinds is to think that membership in said kinds is conferred by microstructural properties. Recently, the received microstructuralist view has been elaborated and defended (for example, Hendry [2006], [2012]), but it has also been attacked on the basis of complexities, both chemical (for example, Needham [2011]) and ontological (for example, LaPorte [2004]). Here, I look at which complexities really challenge the microstructuralist view; at how the view itself might be made more complicated in order to accommodate such challenges; and finally, at what this increasingly complicated picture implies for our standard assessment of chemical kindhood-primarily, for the widespread assumption that chemical kinds in general are more neat and tidy than those messy biological ones.
