Saint Thomas Aquinus ’agen autem non movet nisi ex intentione finis (an agent does not move except out of intention for an end, quoted from Nassim Nicholas Taleb, Antifragile, p. 169.)’. This paper uses the familiar multitasking framework in order to compare contracting with agents holding private information either about their work ethic or intrinsic motivation. Those characterizations are observation equivalent in the absence of incentives but matter once monetary incentives are offered. Indeed the difference is stark: First, incentives change the characterization of which types are efficient or inefficient. Second, contracts in terms of an agent’s work ethic are robust if constraints (ensuring sufficient effort for the unobservable task) are introduced while such constraints can render only fixed wages feasible for intrinsically motivated agents.