concomitance vs train of thought

concomitance

noun
  • A concomitant. 

  • occurrence or existence together or in connection with one another, coexistence 

  • The Roman Catholic doctrine of the existence of the entire body of Christ in the Eucharist, under each element, so that the body and blood are both received by communication in one kind only. 

train of thought

noun
  • The flow of thinking. 

How often have the words concomitance and train of thought occurred in a corpus of books? (source: Google Ngram Viewer )