What is the nature of our world? How does it work? How are we to act and to create in this world? Science has been struggling with providing answers to these and many more questions ever since. Attempting to find explanations for both “internal,” e.g., psychological, and “external,” e.g., physical, phenomena, many scientists have shifted their focus of attention toward interdisciplinary approaches. Interdisciplinary inquiry implies openness which enables the investigator to escape the confinements of a specific discipline in order to become aware of aspects that are necessary to satisfyingly solve a problem. Both, hermeneutic phenomenology and radical constructivism offer perspectives on how to engineer such interdisciplinarity that goes beyond mere multi- or pluridisciplinary approaches. In this paper we carve out the essence of these perspectives, discuss typical problems in contemporary attempts toward interdisciplinarity, and expound how phenomenology and constructivism make genuine interdisciplinary work possible.