Imagining two opposites or contradictory ideas, concepts, or images existing simultaneously is beyond logic. It is a type of conceptualizing in which the thinking processes transcend ordinary logical thinking.

If you hold two opposites together, your mind moves to a new level. The suspension of thought allows intelligence beyond thought to act and create a new form. The swirling of opposites creates the conditions for a new point of view to bubble free from your mind.

This is taken from an interview with Michael Michalko by Vern Burkhardt, http://www.ideaconnection.com/articles/00007-Thinkertoys-Handbook-of-Creative-Thinking-Techniq.html