purpose vs scheme

purpose

verb
  • To have or set as one's purpose or aim; resolve to accomplish; intend; plan. 

  • To have (an) intention, purpose, or design; to intend; to mean. 

noun
  • meaning for existing or doing something. 

  • Resolution; determination. 

  • Function, role. 

  • The end for which something is done, is made or exists. 

scheme

verb
  • To plan; to contrive. 

  • To plot, or contrive a plan. 

noun
  • A council housing estate. 

  • A systematic plan of future action. 

  • An orderly combination of related parts. 

  • A plot or secret, devious plan. 

  • A mathematical structure that enlarges the notion of algebraic variety in several ways, such as taking account of multiplicities and allowing "varieties" defined over any commutative ring (e.g. Fermat curves over the integers). 

  • A chart or diagram of a system or object. 

  • Part of a uniform resource identifier indicating the protocol or other purpose, such as http: or news:. 

  • A representation of the aspects of the celestial bodies for any moment or at a given event. 

  • A portfolio of pension plans with related benefits comprising multiple independent members. 

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