Edward de Bono
A good print-out for schools (can be used on PC courses) on the basic thinking tools: http://www.comp.dit.ie/dgordon/Lectures/SummerCourse2006/Module4_Section2.pdf
'vote' below if you think he should be a 'honorary permaculture designer'
Stella: am not sure about his ethics, but yes I think he's a great designer (and of the type most needed perhaps today) as he has brilliantly designed forms to conceptualize (simplify and universalize) the most crucial bases of design skills: how to think better, more creatively, more flexibly.
eg. I used his ingenious 'carpenters and thinkers' model to illustrate how (goood) designers design ... thinking well = designing well, and deBono has done awesome work on teaching people to think, therefore teaching how to design.
http://www.edwarddebono.com/PassageDetail.php?passage_id=1225 here he mentions master carpenters but doesn´t go into the detail of the book passage... basically good carpenters skillfully use a great variety of tools, they follow principles (distilled from much experience of the carpentry trade, eg. "measure twice, cut once"), they analize each situation, material, etc. wholistically and combine all of these things (materials/elements, tools and principles) into a new creation that perfectly responds to the design objectives that prompted it.
Ej. His work on "designing for Simplicity" could be seen as an extension of the Mini-Max principle
http://noscope.com/journal/2005/05/de-bonos-simplicity-principles