The first edition of the Essay included a brief chapter, "Of Power," dealing with the nature of human volition. Despite the admiration of his friends, Locke expressed both surprise at the direction his thoughts had taken and confusion about the apparent incompatibility of divine omnipotence with human freedom. [Corr. 1592] Revisions made for the second edition made II xxi the longest chapter in the Essay. Locke boasted about his willingness, as a sincere "Lover of Truth," to change his views publicly, yet confessed his remaining puzzlement about the more perplexing aspects of our abilities to think and to move, to produce changes in other things either by performing direct action or by forbearing so to do. [Essay II xxi 71-72] Since human action is "the great business of Mankind" on Locke's view, and since moral responsibility is commonly taken to presuppose some degree of freedom, it is vital for his task to seek some clarity on the nature of human action.
Development of a basic vocabulary for the issue seems clear enough at first. The quasi-relational simple idea of power is present as an element of our observation of any case of change, both as the active force that produces the alteration and as the passive capacity of that which is changed. Since bodies most clearly exhibit the passive power to receive and communicate motion by impulse, our idea of the active power to initiate action derives primarily from reflection upon our own mental operations as we think or move ourselves. [Essay II xxi 1-5] This, Locke held, is the power of volition, or the human will.
The liberty of a moral agent is just its further power either to perform or to forbear any action of thinking or moving according to its own mental preference. Clearly thought, volition, and will are all necessary conditions for having this kind of liberty, but on Locke's view they are not even jointly sufficient, since genuine liberty always presupposes the additional possibility of doing otherwise. Even on those occasions when I do exactly what I want to do, I am not acting freely if there is something that would make me do this whether or not I willed it. It makes no difference whether the determinative force comes from outside me or from the internal operations of my own body, according to Locke, nor whether in compels me to perform an action that might be contrary to my volition or restrains me from performing an action that might be in conformity with my volition. Freedom is the power to do otherwise if my volition were to change. [Essay II xxi 7-13] Although he never addressed the issue directly in the Essay itself, Locke confessed to Molyneux in correspondence that he found it difficult to reconcile the moral freedom of human agents with the presumed omnipotence and omniscience of God. [Corr. 1592]
Notice that on this account of liberty, the cause or explanation of the volition itself is irrelevant, since it is the agent (not the will) that is free. Human beings act freely just insofar as they are capable of translating their mental preferences to do or not to do into their actual performance or forbearance of the action in question. The ability to do as one wills is all that any moral agent could reasonably expect. [Essay II xxi 19-21] Clarity of language, Locke proposed, would forestall the vaunted philosophical dispute about "free will." Since the will is just a power to contemplate possible actions in light of our mental preferences regarding them while liberty is the further power to perform actions in accordance with these preferences, it would be a category mistake to attribute one power to the other. It is only the agent that has the power to will and the power to act, so it is only the agent that is free, not the will. [Essay II xxi 14-16] A demand for freedom of the will is therefore not only absurd but ultimately fatalistic. In particular situations, we must either perform an action or not, and our freedom in doing so is secured in the power to do as we will. If this prior volition were itself another free "action," then it would have to be preceded by yet another, and so on: freedom would be acting in accordance with a volition that was itself freely performed in accordance with a wish that was freely undertaken, etc., etc. . . . ad infinitum. The vicious infinite regress would render freedom impossible. [Essay II xxi 22-25]
What is more, free will would be irrelevant to moral responsibility. Since human liberty is the capacity to act as one wills, agents act freely even when their wills have been determined, so they remain morally responsible and may be justly punished for those actions. [Essay II xxi 56] In a lengthy correspondence with his Dutch friend Philippus van Limborch, Locke repeatedly insisted that emphasis upon the supposed "indifferency" of the will is theologically unsound and morally mistaken. [Corr. 2925, 2979, 3043, 3192] Only the insignificant actions of the insane are truly indifferent, on Locke's view, and the determination of volition is a necessary condition for undertaking any meaningful human action. The more surely volition is determined toward pursuit of the good, the happier the agent will be. (God, for example, is supposed to be perfectly determined to the good, yet is surely also supposed to be free.) In the same way, a proper understanding of the causes of human volition will enhance, not undermine, confidence in our moral accountability. [Essay II xxi 48-50]
In Locke's second-edition treatment of the issue, these causes are clear: human volition is a mental preference that is invariably determined by the greatest present uneasiness attendant upon desire. The presence of pain and the absence of pleasure now, along with the anticipation of either in the future, induce in us a feeling of uneasiness that can be satisfied only by removing the pain or achieving the pleasure. Although we commonly experience many such desires at the same time, each proportional to the degree of pleasure or pain and the likelihood of its production, one among them always overcomes all of the others, and this most pressing uneasiness is the one that determines the will to act in such a way as to resolve it. [Essay II xxi 29-32] If human agents were ever perfectly content in every respect, Locke supposed, they would have no volition and take no action; lacking nothing, they would experience none of the uneasiness that expresses itself in a desire that determines the will to produce a change of circumstances. Thus, the recurrent uneasinesses of hunger and thirst are providential provisions for our survival because they determine our wills toward eating and drinking. Since each uneasiness is experienced as an obstacle to the achievement of happiness, desire for its removal determines the will unless there is another source of uneasiness that overcomes it. [Essay II xxi 34-36]
According to Locke, the simple ideas of pleasure and pain invariably accompany all of our other perceptions, as the delight or uneasiness we experience along with contemplation of every sensory and reflective object of thought. This is a significant provision for the conduct of life, since our native desire for happiness and aversion to misery are thereby guided in determining our wills toward certain thoughts and actions and away from others. This is why we eat good-tasting food and don't burn ourselves on hot stoves. What is more, Locke supposed that our experience of varying degrees of pleasure and pain not only serves us well in this life but also engenders our hope of a better life hereafter. [Essay II vii 1-6] It even provides us with some confidence about the real existence of the external world, since the immediate perception of pleasure and pain is the kind of experience whose involuntary insistence communicates most surely its origin in a source outside ourselves. [Essay IV xi 6-8] It is from successive compounding of these simple ideas, Locke supposed, that we frame the complex ideas of human passions of every sortlove, hate, desire, joy, sorrow, hope, fear, despair, anger, and envy are all modes of pleasure and pain, considered together with notions about the specific circumstances of their origin. [Essay II xx]
On this account of human motivation, the practical efficacy of our morality of good and evil depends upon their perception as pleasure or pain. If it is to have any genuine motive force, moral value, like natural benefit, must ultimately be defined in terms of pleasure and pain. ["Of Ethics in General" 7-8] Good and evil generally are to be considered nothing more than tendencies to produce pleasure and pain, Locke held, and moral good and evil are nothing other than special instances of this association, the reward and punishment artificially annexed by a powerful legislator as the consequences that follow from human actions by virtue of their conformity with or difference from the dictates of moral law. [Essay II xviii 5] The central problem for Locke's hedonism is the human tendency toward a myopic appreciation of our own welfare. Since only present uneasiness can determine the will, the future moral consequences of our actions motivate us only through our present contemplation of the pleasure or pain that they will produce. All too often, our delight in an immediate pleasure or our satisfaction with the removal of an immediate pain override the motive force of remote future consequences. [Essay II xxi 59-64]
The effort to deal with this problem was central to the second-edition account of human volition. Locke withdrew his earlier claim that "the greater Good is that alone which determines the will" in favor of the view that the uneasiness of desire is the proximate cause of every volition, and this requires some careful explanation. [Essay II xxi 42] For readers who might well have preferred the high ground of the earlier doctrine, Locke emphasized that contemplation of an absent future good can still have motive force, but insisted that it can do so only through the mediation of the present uneasiness it induces in us. The difficulty, then, lies in the failure of a perfect proporionality between the felt uneasiness and the greatness of the contemplated good: if it were not so, then mere contemplation of "the infinite eternal joys of Heaven" would invariably motivate us to act only in the achievement of that long-term goal, whereas in fact it is commonly overcome by some trifling yet immediate desire. [Essay II xxi 31-38]
Locke certainly agreed that pursuit of lasting happiness is more important to human life than merely momentary pleasure, but he noted how easily it can get lost among the welter of daily human motives. Pain being felt in the moment always contributes to our present misery, while contemplation of the deferred gratification we hope to achieve from future rewards is not always experienced as present happiness. The onslaught of desires for the more immediate needs of life, as a matter of practical necessity and acquired habit, commonly leaves little room for concern about remotely future goods. [Essay II xxi 43-45]
The natural tendency toward determination of the will by the most pressing immediate uneasiness is not inevitable, Locke proposed, since human agents possess the further capacity "to suspend the execution and satisfaction" of their desires. By providing ample opportunity for reflection upon the relative importance of each desire, this suspencsion of the will in deliberation is vital for the proper conduct of human life. [Essay II xxi 46-47] Like someone who stands still, consults a guide, and then proceeds, we suspend volition, examine our desires, and permit our wills to be determined by the result. The free agent's ability to distinguish real from imagined happiness by due examination therefore rests squarely upon the capacity to suspend the satisfaction of immeditate desires. Once we have undertaken the appropriate deliberation during this period of suspension, Locke held, we have done our duty, and it is right to act upon the volition to which our wills are determined as a result. [Essay II xxi 51-53]
Here Locke distinguished two ways in which a motivating uneasiness may arise in us: either through the immediate effect of an external cause, or through the more lasting consequences to be gained through deliberate contemplation of our future rewards. Moral failure, then, results less often from individual perversity than from excessive haste, which may prevent us from appreciating the present conditions for our future happiness or misery. (Thus, for example, the abstemious Locke supposed that no one would drink too much if the unpleasant future effects of over-indulgence were experienced in the present as vividly as the immediate pleasure of imbibing.) So long as the extent, degree, and certainty of future consequences are not duly evaluated in the suspended state of careful deliberation, we will commonly act in ways that confound rather than produce the happiness we all naturally seek. Securing our genuine, long-term welfare requires cultivation of the habit of deliberative judgment, during which we focus upon the likelihood of suffering the punishments or gaining the rewards attached to contemplated actions by the moral law.
[Essay II xxi 57-70]