Even more than Shakespeare's Iago, John Webster's Bosola seems to represent the early modern theatre's quintessential combination of actor and intelligencer. His self-consciously Machiavellian role in The Duchess of Malfi (1612–13) involves him in negotiating various metadramatic modes. But inversely, and perhaps even ironically, these include significant reflection on the case of the actor who is condemned, or occasionally even prosecuted, for playing the part of the theatrical villain. Iago inspires our interest because ‘his evil is too essential to be changed’, as Robert N. Watson is representative in seeing The very idea of an essential evil here carries existential claims which are bound to certain moral effects and which are conventionally religious in nature. Bosola, on the other hand, commands our continuing interest perhaps partly because of his very human reaction to the noble conduct of the Duchess. As the Duchess's unfolding tragedy informs the development of Bosola's dramatis persona, in some way this complex character's withdrawn conscience wakes and gets the better of him until he is finally able to offer resistance to the role allotted him by circumstances and his employers. If it is his perception of the nobility of the Duchess in her suffering that ‘reawakens his bitterly repressed virtues’, as Watson says, this is partly to do with necessity and in reaction to the neglect of the brothers, who do not value his work to the extent of paying him in full for its execution. It is therefore equally a product of his growing disaffection with the oppressive mechanisms of the state as much as his own crucial role in it which resuscitates his merits in this way.

Since his conversion from the prevailing Machiavellian role of the informing intelligencer comes too late both for the Duchess, and finally for himself, this works as a satirical commentary on the potentially lethal nature of issues surrounding informing. But perhaps more than this, the fact that Bosola's intelligencer does ultimately transform under the dictates of his conscience suggests a nuancing, perhaps even a humanising, of the figure of the informer and intelligencer. Moreover, this takes place even as Ferdinand, who is both his paymaster and the instigator of this intelligencing work, moves in the other direction, towards an increasing bestialisation.