The purpose of this paper is to examine the properties of the agents in Latin impersonal constructions. First of all, explicit agents do occur with impersonal passives. Furthermore, when agents are not explicitly expressed, they are predictable from the context in a number of cases. The occurrence of explicit agents as well as their predictability seems crucially dependent upon the degree of Transitivity of the clause. The verbs that occur in impersonal constructions can be graded according to a scalar notion of Transitivity along a continuum from low-intransitives to high-intransitives. My hypothesis is that the lower the degree of Transitivity of the verbs the lower the referential properties shown by the agent. Moreover, according to my analysis, the category of non-referential agents should be split into two: generic (or universal) agents should be distinguished from non-referential indefinite ones on the basis of the inclusion or non-inclusion of all the participants in the event.