Any curriculum must effect a compromise between two fundamental types of integration: the integrating power of knowers and the integrated structure of knowns. More traditional curriculum arrangements tend to stress the latter, whereas many innovative programs move towards emphasising the former. The pedagogical tension existing between these two emphases, which are neither entirely antagonistic nor completely complementary, is reflected in proposals to integrate the curriculum. Interdisciplinary studies and schemes aimed at unifying an area of understanding take the logical characteristics of differentiated knowledge as their starting point; but entertain quite different assumptions about how it can be integrated. Both these forms of integration are more likely to structure the curriculum by reference to the objective feature of knowledge than by considering the commonsense understandings and interests that particular students or groups of students bring to school with them. By contrast any enquiry based form of curriculum integration inclines toward organising the curriculum exclusively around the perplexities and interests of pupils.