This approach is methodological inductivist essentialism. It results from two principal ideas: from a special version of Aristotelian essentialism as developed by German historism and the view that synthetic and empirical knowledge can only be obtained by the method of induction.
According to the historists' version of essentialism, essences reside within objects, are real, and like seeds contain some potential characteristics that become observable in concrete historical situations.
Being observable, essences can be uncovered, for instance by observing the historical development of objects or institutions.