The relationship between physics and chemistry is one of the perennial foundational issues in the philosophy of chemistry. It concerns the very existence and identity of chemistry as an independent scientific discipline. Chemistry is also the most immediate territory that physics must conquer if its "imperialistic" claim to be the foundation for all sciences is to have any promise. I wish to enhance the anti-reductionist position concerning the chemistry–physics relation with three arguments inspired by the works of some leading twentieth-century chemists. (1) The very foundation of quantum chemistry is classical, and its roots go back to the organic structural chemistry of the 1860s. (2) Chemists exploit for their own purposes the conceptual resources provided by physics; this may or many not involve deducing chemical theory from physical theory. (3) Even physics itself is much more disunified than it may seem, and therefore constitutes a dubious basis for reduction as it is normally envisaged. I will also suggest that a careful consideration of the physics–chemistry relation points to some productive ways in which we can move beyond the reductionism debate as it is traditionally construed in philosophy and science.