gistfile1.txt

   3 1 Building Abstractions with Procedures
   4 ***************************************
   5
   6      The acts of the mind, wherein it exerts its power over simple
   7      ideas, are chiefly these three: 1. Combining several simple ideas
   8      into one compound one, and thus all complex ideas are made.  2.
   9      The second is bringing two ideas, whether simple or complex,
  10      together, and setting them by one another so as to take a view of
  11      them at once, without uniting them into one, by which it gets all
  12      its ideas of relations.  3.  The third is separating them from all
  13      other ideas that accompany them in their real existence: this is
  14      called abstraction, and thus all its general ideas are made.
  15
  16      --John Locke, _An Essay Concerning Human Understanding_ (1690)