In his essay, “The Subject and Power,” Foucault defines the exercise of power as “a mode of action upon the actions of others.” The exercise of power can be either positive or negative. Considered from a positive point of view, it involves the “governing”—understood in the broadest sense as training, shaping, or directing toward a goal or set of goals—of human beings. In these types of power relations, Foucault insists that we are dealing with relations among free subjects. For example, he says,
Power is exercised only over free subjects, and only insofar as they are free. By this we mean individual or collective subjects who are faced with a field of possibilities in which several ways of behaving, several reactions and diverse comportments, may be realized. Where the determining factors saturate the whole, there is no relationship of power; slavery is not a power relationship when man is in chains. (In this case it is a question of a physical relationship of constraint) (“The Subject and Power,” 790).
Power relations presuppose relations among free subjects. One cannot have a power relation with an inanimate object or with a non-human animal. Thus, it seems that power relations can obtain only among human beings because they possess volitional and rational capacities that set them apart from other animals. However, Foucault recognizes that certain social configurations (e.g., chattel slavery) create a situation in which human freedom is so constrained that for all practical purposes it does not exist. However, because Foucault qualifies the kind of slavery he has in view, his position on slavery and power relations is more complicated than it appears on the surface. Foucault’s claim is that “slavery is not a power relationship when man is in chains.” When a slave’s body is bound, and the possibilities for basic physical mobility much less resistance and creative responses are so restricted, he is no longer considered free. Since the (physical) freedom of the slave has been annulled, the relationship is not one of power but of physical constraint. If this is correct, the description does not seem to correspond to historical instances of slavery. Slaves in the antebellum period were of no use to their masters unless they were “free” to work. That is, the slaves were not confined to prison cells or bound in chains for the duration of their enslavement; rather, they were forced to work in the fields for sixteen hours days, to manage the master’s household, and to do numerous other tasks that required physical mobility. Thus, it seems that American slaves were involved at least intermittently in something like a power relation with their masters. This is not to deny that they were at times bound physically (e.g. for beatings); however, the majority of their service for the master necessitated an unbound (physical) existence. In addition, as many slave narratives attest, various forms of resistance were possible within these the constraints of the slave system. For example, slaves often interrupted work routines, stole from their masters, had love affairs with the mistress, attempted to escape, and even physically confronted their masters. Though these and other forms of resistance and response were incredibly risky and could cost the slave his or her life, they were genuine possibilities of action which the slave could choose. One wonders, however, how effective the majority of actions were in terms of social (racialized) structure as a whole. Did interrupting work routines really change the way a slave was viewed in the society? No. These actions, though no doubt important for the slave’s psychological well-being, did not overturn the racial and other mechanisms embedded within the society. These kinds of actions and responses for the most part seem analogous to what Foucault describes in “The Ethic of Care for the Self as a Practice of Freedom,” as “tricks which never brought about a reversal of the situation” (12).
Continuing the passage above and having just described a physical relation of constraint, Foucault says,
Consequently, there is no face-to-face confrontation of power and freedom, which are mutually exclusive (freedom disappears everywhere power is exercised), but a much more complicated interplay. In this game freedom may well appear as the condition for the exercise of power (at the same time its precondition, since freedom must exist for power to be exerted, and also its permanent support, since without the possibility of recalcitrance, power would be equivalent to a physical determination (“The Subject and Power,” 790).
What is unclear to me about this passage is why Foucault says that “freedom disappears everywhere power is exercised.” His conclusion seems to apply to the situation of the slave in chains. That is, power and freedom have no possibility for confrontation because the bound slave is not free; there is no freedom to confront. But why then does he add that freedom and power are “mutually exclusive” and that “freedom disappears everywhere power is exercised”? Repeatedly, he emphasizes that both sides of a power relation must be free (at least to some degree). Thus, freedom is the condition for the possibility of power relations to obtain; freedom makes possible the maintenance of power relations. Perhaps what he means is that in power relationships, e.g., a pedagogical relationship, one side has to willingly take the subordinate role (the student). The student is not forced to learn from the professor, but places himself willing under the professor’s direction. Thus, from the student’s side, when the professor has the “lead” role, the student’s freedom is necessarily limited—but limited by choice. Such a relationship, if it remains positive and productive, does not translate into a dominating relationship, as the student could at any time decide not to listen to the professor’s advice, or s/he could choose to stop attending the professor’s lectures. Also, it seems that the professor must be open to correction by the student. When the professor accepts the correction or challenge to his/her argument, thesis, etc., the student then exerts power (in the Foucauldian sense), which results in a reduction of the professor’s freedom. If this is what Foucault is saying, are we then dealing with a kind of zero-sum game between power and freedom? Foucault does describe the reciprocal relationship between power and freedom as a kind of ongoing provocation and struggle.
The relationship between power and freedom’s refusal to submit cannot, therefore, be separated. The crucial problem of power is not that of voluntary servitude (how could we seek to be slaves?). At the very heart of the power relationship, and constantly provoking it, are the recalcitrance of the will and the intransigence of freedom. Rather than speaking of an essential freedom, it would be better to speak of an ‘agonism’—of a relationship which is at the same time reciprocal incitation and struggle, less of a face-to-face confrontation which paralyzes both sides than a permanent provocation (790).
 “Foucault’s neologism is based on the Greek meaning ‘a combat.’ The term would hence imply a physical contest in which the opponents develop a strategy of reaction and of mutual taunting, as in a wrestling match.—Translator’s note” (p. 790).