In the present paper, we propose an alternative, based on constructivism, to the conventional way of teaching basic physics courses at the university level. We call this approach "coherent teaching" and the underlying philosophy of teaching science and engineering "need-based learning". We have been applying this philosophy in practice in a basic physics course at the Department of Engineering Physics and Mathematics of Helsinki University of Technology. Here we present the main ideas of the new approach and how we have implemented them, as well as discuss how coherent teaching has affected the students' opinions about the course and how it has changed the learning results. (Contains 2 tables.)