"[H]ow free are we in choosing the concepts for formulating our questions? Any scientific work can only be defined by formulating the questions... But in order to formulate the questions we need concepts by which we hope to get hold of the phenomena. These concepts are usually taken from the past history of science; they suggest already a possible picture of the phenomena. But if we are going to enter into a new realm of phenomena, these concepts may act as a collection of prejudices, which hamper progress... Even then we have to use concepts, and we can't help falling back on those given to us by tradition."