When historicism goes bad

Five deeds that make this historicist (of undetermined vintage) sad, especially when she finds herself committing them. 

• The two-to-three sentence appeal to "context," entirely couched at high levels of abstraction.  Despite walking like ducks and talking like ducks, such gestures towards context are not, in fact, ducks.  A generalization about a particular set of decades does not necessarily yield any relevant data about those decades, let alone the year(s) in which the literary text at issue was written, published, and read.  In particular, this tactic tends to freeze ongoing conflicts into static agreements, or confuse respectable dissents with transgressive arguments.  For example, generalizing from what one set of Victorian evangelicals thought about marriage to what all Victorian Christians thought about marriage results in some rather unfortunate distortions.
• The flattened citation.  One of the perils of interdisciplinary study is that we forget that other disciplines have their own internal arguments.  And thus we have a bad habit of falling back on secondary sources without, it seems, knowing their disciplinary contexts--especially if the secondary source in question lies outside our own purview. 
  
• The non-existent citation.  That is, vast generalizations about the State of the Universe in 1903, or something of the sort, all of which appear to derive from common (textbook?) knowledge instead of, well, a source. 
• Theory as evidence.  Jameson may have said that something is so.  But is it so?  This sort of theoretical fundamentalism, for lack of a better word, is hardly confined to those of us who self-identify as historicists, but it's certainly more glaring when we indulge in it. 
  
• The one-thinker universe.  E.g., all of Enlightenment philosophy boils down to Locke, all of Victorian Catholicism boils down to Newman, and so forth.  A subset of this problem would be the "irrelevant one-thinker universe," in which the critic places her author(s) in "dialogue" with a writer whom s/he very likely would not have known--or, perhaps, understood.  There are ways of and reasons for doing such a thing, of course.