Throughout the day, we are forced to deal with numerous new impressions and experiences. In order to get to grips with the chaos that characterises the world around us, we are constantly on the lookout for connections and patterns. Based on those, we are able to classify reality and create order. Scientists draw up similar classifications. However, these need to be underpinned by clearly defined criteria which will determine in a straightforward way whether or not something belongs to that classification, and, if so, where. Now, you might wonder: does that order truly exist? Alternatively, do scientists impose said order on reality?