This text deals with a problem concerning processes of the productive power of knowledge. We draw on the so-called poststructural theories challenging the classical image of thought--as hinged upon a representational logic identifying entities in a rigid sense--when formulating a problem concerning the gap between knowledge and the object of knowledge. More specifically we are looking at this problem in the contexts of sustainable development and childhood, using illustrating examples in order to test the validity of these theoretical accounts. The examples we use range from internationally agreed documents claiming universality concerning environmental protection and childhood to national curricula for the pre-school to a Swedish governmentally produced and distributed TV series called "Needle and Stick save the world," addressing the issue of sustainable development. In short, we wish to problematise the rigid positions of the child and the human being in relation to nature. (Contains 2 notes.)