First of all, we would like to thank Alexander Renkl for taking the time to read and comment on our special issue on the effects of constructivist learning environments. Such responses indicate that our special issue has been successful in at least one of its goals: It has stimulated further debate about the nature and characteristics of constructivist learning (environments).We find it difficult to disagree with several of the points made by Renkl (2009), given that we share the same view to a large extent. However, in this commentary we will explain that in our view, there is not necessarily a paradox when constructivists talk about constructivist learning environments. In our opinion, it all depends on how one views and approaches constructivism and we will argue that three perspectives can emerge in this respect: A theory of learning, a philosophical position, and a theory of instruction.At the same time, we agree that the term ''constructivist learning environment'' might raise some false expectations. Other labels to refer to what we have called ''constructivist learning environments'' might be helpful in this respect, e.g., new learning environments or learning environments that foster meaningful learning.In our introductory article for the special issue, we clearly distinguished between constructivism as a learning theory and educational applications of this theory, i.e., constructivist learning environments (Loyens and Gijbels 2008, pp. 351-352). By making this distinction, we tried to keep theory and pedagogy apart. We concur with Renkl that educational applications such as the use of meaningful problems do not belong to the epistemological core of constructivism. In our view, however, introducing epistemology when discussing constructivism is adding a third perspective besides a theory of learning and a theory of instruction.