A humanist theory of science must satisfy two requirements which appear to be in tension. Firstly, in order to hold science accountable for its socio-political consequences, it must challenge narratives presenting science as objective and value-free. Secondly, in order to hold scientific knowledge as authoritative when deciding on public policy, it must challenge narratives presenting science as biased and unreliable, e.g. climate science denial or anti-vaccination rhetoric. I show that pragmatist philosophy can answer these apparently contradictory needs. Rather than taking science as a means of objectively representing an external world, pragmatism would hold that scientific method has evolved through human attempts to navigate their material environment, with increasingly abstract and broadly applicable practices for successful goal-achievement being honed and systematized in the process. So, while science’s proper function is to serve value-based purposes, it is nevertheless a method which carries authority in determining appropriate actions for navigating encountered problems.