It is known that the real 6-dimensional space of screws can be endowed with an operator E, E 2 = 0, that converts it into a rank 3 module over the dual numbers. In this paper we prove the converse, namely, given a rank 3 module over the dual numbers endowed with orientation and a suitable scalar product (D-module geometry), we show that it is possible to define, in a natural way, a Euclidean space so that each element of the module is represented by a screw vector field over it. The new approach has the same effectiveness of motor calculus while being independent of any reduction point. It gives insights into the transference principle by showing that affine space geometry is basically vector space geometry over the dual numbers. The main results of screw theory are then recovered by using this point of view. As a case study, it is shown that D-module geometry is effective in deriving results of Euclidean geometry. For instance, in a pretty much algorithmic way we prove classical results in triangle geometry, among which, Ceva's theorem, existence of the Euler line, and Napoleon's theorem.