A discussion of some of the unconsciously held beliefs or "presuppositions" which contribute to human decision-making, usually without the awareness of the decision-makers. Building on the work of Peirce, Gibbs, Lemoigne and Argyris, the author proposes a methodology of generic design science be used to dislodge those "uncommendable" presuppositions on the part of designers & planners which have contributed in the past to disastrous planning and disastrous decisions. Warfield was unable to attend this conference, but the paper was presented in Vienna by his colleague and friend, W. Gasparski, and it was later published in the conference proceedings. The original manuscript for this article was written in September 1989. Included in the file folder are some sketches and hand printed transparencies which were drawn by Gasparski, and used by him when presenting the paper. Rose Warfield found an offprint while unpacking in 2013 and is going to go ahead and scan it now 11 April 2013 and hope I can located and identify Gasparski figures to add to the scan later. Will save the hard copy in plastic bag notebooks box of stuff I put off until the last from Warfield's old note-binders.