Hi, I believe the first definition for orthogonal is not the vector or Cartesian definition but rather from geometry. Where, for example, polygonal means a closed shape made up from many line segments, orthogonal means a closed shape made from line segments at right angles to each other. The simplest being the square. DeCarte used the concept of ortho- to describe the relationship between the axis of his measurement system, hence orthogonal. Strictly speaking orthogonal is a misnomer and should be orthometric or 'measurements at right angles'. I am interested in how orthogonal obtained its variety of other meanings. I run across it in linguistics, computer science, philosophy, etc. In most of them it means some sort of pure or simple relationship. Unfortunately I can't find any sort of description of how it got expanded this way. ____________________________________________________________________ | | | The financial policy of the welfare state requires that there | | be no way for the owners of wealth to protect themselves. | | | | -Alan Greenspan- | | | | _____ The Armadillo Group | | ,::////;::-. Austin, Tx. USA | | /:'///// ``::>/|/ http://www.ssz.com/ | | .', |||| `/( e\ | | -====~~mm-'`-```-mm --'- Jim Choate | | ravage@ssz.com | | 512-451-7087 | |____________________________________________________________________|