Action, Reaction, and Reflex
Analytical philosophy of action typically begins by distinguishing between mere reflexes and intentional actions. The blink reflex and the patellar reflex involve bodily movements with no psychological intermediaries, while bodily movements like directing traffic are prompted by beliefs and desires. The philosopher then declares that he or she is interested in the latter not the former—they are not really actions at all. The thought is that reflexes are elicited by external stimuli in a mechanical manner—no deliberation, no choice, and no freedom—while intentional actions are psychologically produced and do involve deliberation, choice, and freedom. Putting it in terms of causation, reflex behavior is caused by external non-mental stimuli while intentional action (action proper) is caused by internal mental states like belief and desire. The philosophy of action is then held to concern itself with the latter type of behavior. Maybe reflex behavior is grudgingly allowed to count as action in a colloquial sense (“reflex action” is not contradictory), but it is not deemed to be action in the proper philosophical sense—and so it does not belong to the philosophy of action.
But there is another category of behavior that fails to fit neatly into this dichotomy, which is seldom if ever discussed. I mean what we can call reactive behavior: reactions, in short. There are spontaneous actions that are performed without any prompting stimulus—stimulus-free actions in one terminology—and there are actions that result from an external occurrence. For example, there are reactive acts of speech such as responding to a question or accepting an invitation, as there are reactions like rushing to help someone in distress, or flaring up at an insult, or holding up your hand to protect your face, or laughing at a joke, or slamming on the brakes when a car suddenly stops in front of you. The action would not have occurred but for the impinging stimulus, and it is appropriate to that stimulus; it is not spontaneous and stimulus-independent. Yet it is not a reflex: it has psychological antecedents, and is not a matter of a mere reflex arc. The agent perceives that something is happening and reacts to it, presumably motivated by some sort of desire; and it is possible to train oneself not to so react, unlike with genuine reflexes. People say, “I didn’t think, I just reacted”, thus distinguishing the case from fully voluntary free deliberative action; but they don’t suppose that the action was brought about purely from a mechanical external stimulus. The stimulus may have made the agent angry or fearful or amused, and this is what led to the reaction in question. So the external stimulus led to an internal mental state that was necessary for the reaction to occur. What we have here is something intermediate between the standard categories of intentional action and mere reflex, which has not been much explored. It fits into neither category; specifically, it doesn’t fit the paradigm of the spontaneous action prompted by belief and desire. An explanation of a reaction will not then mirror the explanation of a spontaneous action: it will refer not merely to internal belief and desire (if indeed it does this at all) but also to an eliciting external state of affairs. “Why did you raise your hand to your face?” “Because I was about to get hit in the face by a ball.” No doubt you desired not to get hit in the face, and no doubt you saw the ball coming; but it is also true that your action was a reaction to a stimulus. This was a stimulus-controlled non-reflex action: a hybrid, an intermediate case.
As always the dictionary (OED) proves useful. For “action” we find: “the process of doing something to achieve an aim”. For “react” we find: “respond to something in particular way”; for “reaction” we have: “an instance of reacting to or against something”. For “reflex” we have: “an action performed without conscious thought as a response to a stimulus”. From these definitions we see how reactions sit between actions and reflexes, conceptually speaking. Note that reactions are not said to “achieve an aim”, presumably because they can be unwise and counterproductive: they may go against the agent’s interests and considered judgment. The agent may regret and lament their occurrence (“Sorry, m’ lord, I just lashed out when he insulted my mother”; compare, “I didn’t mean to kick the dog but someone tapped my knee with a hammer”). Note too that there is no hesitation in describing a reflex as an action, just an action performed without conscious thought. The reason this raises no eyebrows is that reflex behavior is purposive: it is precisely not like merely mechanical causation such as we find in the physical world. The eyelid blinks in order to protect the eye; the knee jerks upward because the tendon is designed so as to aid balance, the jerk being a side effect of that. By contrast, rivers don’t erode banks so as to widen rivers, and meteors don’t cause craters in order to pockmark the earth’s surface. The right thing to say, clearly, is that there are three types of action: reflex action, reactive action, and spontaneous action. All are unambiguously action, but there are three distinct types of action. The philosophy of action should concern itself with all three types, noting their similarities and differences; focusing exclusively on spontaneous action is a mistake. In particular, the case of reactive action needs to be brought to the fore. What should we say about crying or salivating? Are these reactions instances of action? They can be controlled to some degree, yet they seem close to involuntary reflex actions. What about biting and swallowing in response to food in the mouth? Is the response of turning down a Nobel Prize a case of reaction to a stimulus? Does all reaction involve desire—for example, screaming when hurt? How does belief feature in reactive action?
It has often been pointed out that actions can be purely mental, as when you calculate in your head. Is the same true for reactions and reflexes? The answer is affirmative: you can react to an insult by plotting to get your revenge, or promise yourself not to visit places where temptation may lead you to act in ways you later regret; and surely the elicitation of pain or visual sensation is a matter of reflex (though these are not strictly actions). The mental analogue of reflex action would be automatically judging that something is so simply because you have seen it to be so: immediate and unthinking, yet active. Animals may be more prone to such purely mental reflexes than we are, what with our advanced rationality. So the subject of mental action needs to reckon with all three types of mental action not just the spontaneous kind. There are responsive mental actions as well as stimulus-free mental actions. Weakness of will too can apply to reactive actions as well as to the spontaneous kind: indeed, reactions more often involve doing things against our better judgment. And this can hold for mental as well as bodily actions. Linguistic actions can also fall into the three categories, whether bodily or mental. Much linguistic behavior is reactive—not like the standard case of making an assertion out of the blue. Conversation is precisely reactive verbal behavior: answering questions, responding relevantly, filling in silences. And verbal reaction can occur purely in the head: responding verbally to perceived events in one’s own mind, keeping on topic in one’s internal soliloquies. It is a question whether any verbal behavior may be aptly described as reflexive, whether internal or external: are speech acts ever mechanically elicited by a stimulus “without any conscious thought”? Perhaps infants do this for a while by uttering words at the mere sight of a stimulating object (“Dada!”), and some aphasics are prone to uncontrolled verbal output when a stimulus is presented. Are there words we can’t help saying inwardly when something agreeable or disagreeable happens? Verbal behavior is not generally of a reflexive nature, but there may be outlying examples of it where reflexes kick in. Could such reflexes be conditioned in subjects? In any case, verbal behavior is often reactive—in which case we should speak of “speech reactions” as well as “speech acts”.
Now an interesting question suggests itself: reactions are a type of action, but are actions a type of reaction? I don’t mean a reaction to an external stimulus, since that is clearly not true, but are those the only kind of stimuli there are? What about internal stimuli? Certainly we can react to states of our own body, as when we scratch an itch or moan in pain; and obviously you can respond to a medical problem by seeking professional help. But is there anything internal that actions in general might be construed as a response to? Indeed there is: desire. Organisms have needs, say for food and sex, and these get expressed as desires accompanied by sensations such as feelings of hunger. All this takes place outside of the organism’s volitional faculty, but it feeds into that faculty. We might speak of this as the internal environment, the desire landscape–and the animal can react to this environment. It can react by trying to modify the internal environment, by meeting the needs expressed therein. This is where action comes in: action responds to the stimulus provided by the internal environment of need and desire along with accompanying sensations (some highly disagreeable). Thus action is reaction to desire. It is a response to desire, an engagement with it, an interaction with it. In principle, an experimenter could intervene to modify the internal psychological environment in order to control the animal’s behavior, as the external environment can be so manipulated. Theoretically, the cases are on a par: behavior is a response to environmental variables, both outer and inner. So spontaneous action (so-called) is really a type of reaction to a stimulus—the internal stimulus of desire. If so, the basic concept of action theory is reaction: all action is a response to something—there is no such thing as completely spontaneous action. It is true that actions can be stimulus-free with respect to external stimuli, but these actions are always stimulus-bound with respect to internal stimuli (so no support to behaviorism here). Or perhaps we should not use the word “bound” because there is some looseness in the stimulus-response connection (unlike the case of reflex); rather, the action is stimulus-directed (influenced, regulated). Just as I might decline to react in a certain way to an impinging contingency, so I might decline to act on a desire that is pressing its claim to expression; still, when I do act on such stimuli it is because of them that I do so. The action is always stimulus-triggered when it is triggered; it is not a reaction to nothing. Accordingly, the philosophy of action is the philosophy of reaction. To put it differently, the will is a reactive faculty.
If we follow this line of reasoning, we can see an element of truth in the behaviorist’s view of the mind: not indeed the doctrine that the mind is external behavior, nor yet the theory that all learning is conditioning, nor even the idea that there are predictive laws of behavior—but the thought that the mind is essentially a reactive being. The organism must react to its environment in order to survive, and that environment includes its own internal state—thus feeding behavior results from both internal hunger and the presence of external food material. The mind must orchestrate these interactions, reacting appropriately to the prevailing conditions: it must adapt itself tothem. Thus in a certain sense it is true to say that psychology is stimulus-response psychology: that granule of truth was then distorted and exaggerated by the behaviorist school. But that misguided school was at least partly grounded on an idea that it is not intuitively wide of the mark, viz. the mind is essentially a reactive organ (like other organs). The mind is a responsive thing, acting in relation to things, taking the measure of things (external or internal). If the essence of life is adaptive reaction, then the mind is one aspect of this biological principle. Action then is like a reply to a question.
 Psychologists often speak of avoidance behavior and approach behavior, thus registering the reactive nature of much behavior; other forms of behavior make no reference to any object in relation to which the organism is acting in these ways, such as singing or playing football. Reactive behavior, which is stimulus-driven, is thus classified into two types, according as it involves attraction to the stimulus or avoidance of it. Not all reactive behavior falls into these two types, however, as with responding angrily to an insult.
 A good example from literature occurs in Melville’s Billy Budd. The evil Claggart falsely accuses Billy of mutiny in front of Captain Vere and the Captain asks Billy to respond to the accusation. However, Billy suffers from a speech impediment in situations of injustice like this and can say nothing in reply. Melville writes: “The next instant, quick as the flame from a discharged cannon at night, his right arm shot out, and Claggart dropped to the deck”. Clearly Billy’s action was reactive, but notice also that Melville compares it to an inanimate event and describes the action as if it were disengaged from Billy’s rational faculties—his arm “shot out”. This is precisely the kind of action I have in mind. (Despite the circumstances, Billy Budd pays for his arm’s reactive action with his life.)
 Compare increasing the intensity of an external stimulus with increasing the intensity of an internal stimulus: if the stimulus is unpleasant (as in those unethical experiments using electric shock or food deprivation), the animal’s behavior will be modified accordingly, as it reacts to the variation in the stimulus. The cases are entirely parallel.
 The contrary view, which emphasizes the spontaneity of action, might be said to compare action in general to the speech act of assertion—a type of speech act that is not characteristically a response to anything. According to the reactive view, by contrast, perception poses questions to the motor system, to which it must reply appropriately; and desires pose questions too, along the lines of “Won’t you act on me, please?” Call this the “interrogative model” of action just to have a fancy name. Then the interrogative model proposes that all action consists of reaction—a response to a questioning stimulus. More literally, it views all action—spontaneous, reactive, and reflex—as having a stimulus-response structure (sans behaviorism, of course).