The paper addresses the problem of the justification of the normativity of instrumental imperatives. Husserl criticizes the Kantian attempt to justify the normative force of this type of rationality requirements through a mere semantic analysis of what willing an end means. The genetic constitution of the concept of means and, derivatively, of instrumental imperatives, would, on the contrary, involve the cooperation of logical and emotional acts. Thus, the paper argues that the functional structure of volitional reason becomes intelligible only on the basis of the convergence of those two elements, insofar as it is a faculty that can be referred to practical intentions with alleged causal eficacy.