If science always insists that a new order must be immediately fruitful, or that it has some new predictive power, then creativity will be blocked. New thoughts generally arise with a play of the mind, and the failure to appreciate this is actually one of the major blocks to creativity. Thought is generally considered to be a sober and weighty business. But here it is being suggested that creative play is an essential element in forming new hypotheses and ideas. Indeed, thought which tries to avoid play is in fact playing false with itself. Play, it appears, is the very essence of thought.This notion of falseness that can creep into play of thought is shown in the etymology of the words illusion, delusion, and collusion, all of which have as their Latin root ludere, "to play." So illusion implies playing false with perception; delusion, playing false with thought; collusion, playing false together in order to support each other's illusions and delusions. When thought plays false, the thinker may occasionally recognize this fact, and express it in the above words. Unfortunately, however, our English language does not have a word for thought which plays true. Perhaps this is a reflection of a work ethic which does not consider the importance of play and suggests that work itself is noble while play is, at best, recreational and, at worst, frivolous and nonserious. However, to observe children at play is to realize the serious intensity of their energy and concentration.