I think that the heart of Bolt's drama is the collision between transcendent idealism and practical materialism.  Sir Thomas More is depicted as a figure who will not sacrifice his beliefs.  While it would be politically convenient for More to embrace a civil authority over a sacred one, More refuses to acquiesce to such a notion.  His idealism compels him to accept death than to sacrifice or mitigate his beliefs.  The "moral squint" that is described is actually a representation of idealism that is a constant.  Recall More's admonishment of Roper for abandoning ideals when times are trying:

More chides Roper for anchoring to his principles, but pulling up anchor and moving elsewhere when the 'weather turns nasty."

It is here where More is a "man for all seasons."  More's idealism makes him unlike the common man, who benefits as things change and who represents a moral malleability that enables him to benefit greatly from such pragamatism.  This idealism is also in stark contrast to Richard Rich, who is more concerned with his own material advancement than any other moral code.  His perjury compels More to feel worse for him than anything else because More recognizes in his amorality that there is nothing reflecting the essence of human identity.  In the end, the moral play that happens in this drama is one where idealism to collective nobility is challenged and confronted by a world that is increasingly self- interest based and one that is more pragmatically driven by materialism.  In the end, the audience must assess what it means to be "a man for all seasons."  While Bolt feels our world is more contingent and ironic, he seems to be compelling the audience to ask, through understanding More's character, if this is how consciousness should be as opposed to what it is.