Are Buddha nature and Original enlightenment different, or always identical? Are Buddha nature and Original enlightenment different, or identical?
So, when a sastra says &quot;Since the essence of Mind is grounded on the Dharmakaya, it is to be called the original enlightenment&quot;, is the exact same the case for Buddha nature?
When a Soto monk says &quot;manifest buddha nature&quot;, do they mean &quot;manifest original enlightenment&quot;?
Yes.  The difference in terms just highlights a difference in emphasis.  All zen teachings basically point to the same thing.  The difference is dependent on what obstacle the teacher is pointing too.  For someone who is always striving, a teacher might call it original mind to emphasize that he is already in possession of what he's striving for.  For someone who thinks zen is about rarefied states or accomplishments, a teacher might call it ordinary mind.  For someone who is caught up in intellectualizing, he might simply hold up a flower.
Its all the same shit - namely the shit you are caught up in.