Philosophers have been concerned about the nature of emotion since Socrates and the pre- socratics. Indeed, while philosophy has grown up largely as the pursuit of reason, the emotions have always lurked in the background - often being seen as a threat potentially enslaving reason. There are two aspects to this. First, emotion has often been seen as inferior, primitive, unreliable, and dangerous - in need of control by reason. Secondly, emotion has traditionally been seen as somehow different - as distinct from reason altogether (e.g. two conflicting and antagonistic aspects of the soul). Even those philosophers who attempted to reduce one to the other (such as Hume's "distorted judgement") maintained this distinction by continuing to insist on the superiority of reason.

Today I would like to trace the history of philosophical attempts to deal with emotion, followed by a brief summary of questions still central to philosophical debate. Before we begin it is important to consider that different philosophers have focused more on different aspects than others (e.g. cognition, sensation, physiology, social and behavioral). It is also important to recognize that the word "emotion" or "passion" does not always translate exactly, and that not all philosophers have developed full-blown theories of emotion - rather some have only focused on specific emotions and ignored the rest.

With these caveats in place, we begin with the Greeks. The emotions as such do not form one of the three aspects of Plato's divisions of the soul (reason, spirit and appetite). This treatment of emotions in the Republic not only seems divided between spirit and appetite, but, given his treatment of eros in the Symposium, it would appear that he conceived of emotions operating in the exercise of reason as well.

Aristotle, in contrast, defined emotion in his treatise on Rhetoric as "that which leads one's condition to become so transformed that his judgement is affected, and which is accompanied by pleasure and pain" (e.g. anger, fear, pity). Aristotle discussed certain emotions at length (e.g. anger, which he described as "a distressed desire for conspicuous vengeance in return for conspicuous and unjustifiable contempt of one's person or friends...always directed toward someone in particular"). But the key to Aristotle's analysis is his notion of a "slight." In his view, this "scorn, spite or insolence" - real or imagined -is the cause of anger, and the resultant desire for revenge. Indeed, Aristotle's analysis of anger seems to have anticipated most of the main contemporary theories in many aspects: it includes a distinctive cognitive component, a specified social context, a behavioral tendency, and a recognition of physiological arousal (e.g. he also recognized that physical or psychological discomfort predisposed people to anger).

But the most important single point is that Aristotle's analyses only make sense in the context of his broader ethical concern. He was interested in anger, for example, as it is a moral force that can be provoked by both rhetoric and reason. Moreover, in his work on ethics, he argues that there are

circumstances in which it is appropriate to get angry, and in which the absence of anger is a vice, not a virtue. (given his typically Greek view of virtue as the "mean between extremes"). The emotions, in other words, are central and essential to the good life, and the analysis of their nature part and parcel of an ethical analysis.

As we move forward into Roman times, we find this conjunction between emotion and ethics again in the philosophy of the Stoics. However, while Aristotle took emotion to be essential to the good life, the Stoics analyzed emotions as conceptual errors that encouraged misery. Individuals like Epictetus, Seneca, Chrysippus and Marcus Aureleus developed a full-blooded cognitive theory of the emotions where emotions were seen as judgements about the world and one's place in it. Since the world of Roman society was often not a happy place to live, the stoics saw the world they lived in as out of control, and the expectations inherent in emotions as misguided judgements (the vulnerability inherent in love; the desire for security inherent in fear). Instead, they strove for the ideal of "psychic indifference" to things that were temporary and insecure. While believing in a "higher reason" transcending this world, they felt that the best life that could only be achieved here by getting straight about the ultimate pointlessness of emotional attachments and involvements.

As we move into the Middle Ages, we find the study of emotion still attached to ethics - this time from a more Christian standpoint. There were elaborate physiological analyses of the effects of the various "humors" on emotional temperament, as well as rich cognitive studies of the emotions. Emotions were essentially linked with desires -particularly self-interested, self-absorbed desires. Indeed, the Christian preoccupation with sin often lead to elaborate analyses of those emotions, passions and desires designated as sins (e.g. greed, gluttony, lust, anger, envy, pride and sloth). Curiously, the highest virtues such as love, hope and faith were elevated to a plane beyond emotion and often equated with reason (e.g. by Thomas Aquinas).

In the 17th century, Descartes dismissed all earlier work on emotion as "far from credible" and started from scratch. Essentially a scientist and mathematician, he was impressed by reason and disdained the bodily and bestial. Indeed, he argued that the mind is a separate "substance" from the body. However, in attempting to deal with emotions he had to explain how the mind and body interact. His argument was that the mind and body meet in a small gland at the base of the brain (the pineal gland), and that each affect the other by means of the agitation of minute particles of blood which bring about the emotions and their physical effects in various parts of the body. However, the emotions involve not only the sensations caused by this physical agitation, but perceptions, desires and beliefs as well (e.g. the perception of a threat and a desire to avoid it). Hence, an initially physiological account is combined with a cognitive account. Emotion was seen as useful when it encouraged or buttressed rational thought or action, but still potentially dangerous if it distracted such a focus and led people astray.

Descartes' contemporary Baruch Spinoza, like the earlier stoics, saw emotions as misguided judgements about life and our place in the world. He felt that emotional "thoughts" often misunderstand the world and thus, render us miserable and frustrated. However, unlike the stoic aspiration to psychic indifference, he argued that we can only experience "bliss" once we get straight our thinking about the world. We must give up the idea that we are or can be in control of our lives, and adopt the all embracing idea of ourselves and our minds as part of God. Most of the emotions, which are passive reactions to our unwarranted expectations of the world, will leave us hurt and frustrated. Active emotions, in contrast, emanate from our own true natures and heighten our sense of activity and awareness. Essentially, Spinoza, along with the stoics, developed an early version of the cognitive theory of emotion.

David Hume, the famous Scottish skeptic, holds an interesting position in the philosophy of emotion in that he used reason to attack reason itself. In so doing, he took a fresh look at emotion. For example, he argued that it is not reason that motivates ethical behavior, but our emotions ("reason is, and ought to be the slave of the passions"). While defining emotion as a "sensation" or "impression," this must be given meaning by reference to the individual's whole complex of impressions and ideas (e.g. his analysis of pride as an impression on the self that one has achieved or accomplished something significant). Hume acknowledged the cognitive and the physiological dimensions of emotion, along with sensations. Moreover, his inclusion of the of the idea of the self in his analysis of pride indicates his grappling with the idea of intentionality (or the "aboutness" of emotion).

The emotions, for Hume, also form an essential part of ethics (pride is good/humility is "monkish"). Hume and his contemporary, Adam Smith, defended the importance of the moral sentiments such as sympathy ("our ability to feel with other people and appreciate - if not suffer with - their misfortunes"). Sympathy, they argued, is a universal feature of human nature, countering and mitigating self-interest - and is the foundation of society and morality. Emotion is not an embarrassment to be unfavorably contrasted and opposed to reason, but something to be celebrated and defended along with it.

Immanuel Kant was uncompromizing in his defense of reason against Hume's skepticism. He did not like Hume's attempt to ground ethics on fleeting human feeling instead of the universal and necessary dictates of reason. As such, his work largely reinforces the traditional distinction between reason and what he saw as the "inclinations" (emotions, moods and desires). He saw these as inessential to morals at best and intrusive and disruptive at worst. Nevertheless, his largely disparaging references to the "inclinations" are a bit more ambiguous than usually supposed (e.g. in aesthetics he celebrated the importance of shared feeling in the appreciation of beauty, and once declared that "nothing great is ever done without passion"). Indeed, Kant's successor Hegel again called into question the overstated distinction between reason and passion in the early 19th century.

In the mid-19th century Friedrich Nietzsche took things to the other extreme in his celebration of passion and suspicion of reason. The culmination of a long line of "romantics," Nietzsche anticipated the global skepticism and conceptual chaos of the 20th century, describing and celebrating the darker, more instinctual and less rational motives of the human mind. For example, he praised the passions, and, in an ironic twist, described the passions as themselves having more reason than reason. While he concedes that some passions "drag us down with their stupidity" - most notably the "slave morality" that levels the virtuous passions and defend mediocrity. While never developing a theory of emotion as such, Nietzsche's celebration of passion scared many people - who saw it as a precursor to the wars and extremism of the 20th's century.

In the 20th century philosophical treatment of the emotions followed two different trajectories in Europe and the English-speaking world. In North America and England the emotions were downplayed largely because of the newly exaggerated emphasis on logic and science. While emotion was a major concern of William James in the early 1900's (who saw emotion as a sensation caused by a physiological disturbance prompted by a perception), the development of psychology as a separate discipline relegated questions about emotion to that field. But more significantly, Anglo-American philosophy became dominated by "logical positivism," an approach that dismissed ethical, emotional, and many other philosophical questions as meaningless (if "unscientific and without verifiable solutions"). In the English speaking world, emotions came back onto the stage of philosophy, but only as the butt of the argument. Ethical statements, for example, were seen as meaningless because they were seen as nothing but expressions of emotion.

In Europe, however, the emotions enjoyed more positive attention. Franz Brentano, for example, followed Hume in attempting to found an ethics on a foundation of emotions. Following the phenomenology of Edmund Husserl, thinkers such as Max Scheler, Martin Heidegger, and Paul Ricouer developed philosophies in which emotions were given a central place in human existence and accorded considerable respect. Heidegger, for example, defended "moods" as our way of "being tuned" to the world. Jean-Paul Sartre wrote of emotions as both "magical transformations of the world" and willful stratagems for dealing with difficult existential circumstances.

Today one finds a rich variety of arguments about emotions on both sides of the Atlantic. Given the nature of philosophy and its current concern with epistemological matters, the philosophical focus is again on the conceptual structures of emotion, rather than its sensory, social and physiological aspects. Yet there has also been a reaction against "hypercognizing" emotion, and serious efforts made to join forces with psychologists, neurologists, anthropologists and moral philosophers to obtain a more holistic theory of emotion.

Now that we have sketched the historical development of the philosophy of emotion, we turn to consider briefly some of the key philosophical questions.

First and foremost is the definitional question: What is an emotion? More broadly, how should we think about emotion - as intrusive, dangerous, dispensable, and an excuse for irresponsibility? Or as essential to our rationality, constitutive of meaning; and a mode of responsibility?

Secondly, which of the evident aspects of emotion should we take to be essential? (e.g. physiological, sensory, behavioral, cognitive, and social). Some have focused largely on introspective work, while others, following social scientists, have pushed for a more public analysis of observable criteria. Going hand in hand with this, philosophers have formulated their own versions of behaviorism, psychologism and social construction theory.

Third, can one have an emotion without feeling? How specifically are emotional feelings tied to physiological processes (e.g. happiness). How do we test for these? Do tests matter?

Fourth, how are feelings structured? While this may emerge in thoughts and verbal expressions, how much is this learned and superimposed on more general physiological sensations? (e.g. feelings typical of fear and anger do not actually constitute fear or anger if there are no appropriate beliefs accompanying them). Are physiological feelings or sensations then insufficient to constitute emotion on their own? Recent advances in neurology add to debates about such questions - so much so that there is now an interdisciplinary subfield called "neurophilosophy."

Fifth, and in a similar vein, while virtually all emotions get expressed (at least minimally) in behavior, should behavioral tendencies or sequences be taken as essential? Some would argue that facial expressions are "hard wired," or that emotion is nothing but a behavioral expression, while others suggest that the symptom is not the cause - perception and awareness is really what causes the twitch or gesture. Similarly, isn't emotion, at least in part, a value-laden description of a social situation? (e.g. shame and embarrassment).

What is at the core of all such theories, however, is an awareness that all emotions presuppose or have as their preconditions certain sorts of cognitions (e.g. an awareness of danger in fear, recognition of an offense in anger, appreciation of someone or something lovable in love). Even the most hard-headed neurological or behavioral theory must take account of the fact that no matter what the neurology or the behavior, if a person is demonstrably ignorant of a certain state of affairs or facts, s/he cannot have certain emotions. This is known as the "formal object" of emotions - the minimum essential set of beliefs defining an emotion and an emotional experience. While the exact nature of formal objects and requisite beliefs of various emotions are matters of lively debate, the presumption is that every emotion must have a cognitive basis and an object.

Of course, there is also considerable debate over the nature of cognition itself. Beliefs seem to be established states and therefore lack the spontaneity that characterizes many emotions. They also seem to be too fully articulate for the unreflective reactions that characterize most emotions. For that reason, thinkers play with words such as "judgement, thought, evaluation, perception, and/or seeing as." These may either reflect a partial rejection of the cognitive view, or more precisely, refinements of it. The nature of an emotional cognition, and whether it must be fully conscious or capable of articulation, remain matters of considerable debate.

One way of putting the issue of the cognitive component in emotion is to suggest that they cannot simply be feelings, physiological processes, or even mindless bits of behavior. Instead, they exhibit intentionality: emotions are always "about" something or other (e.g. one is angry about something; is in love with someone, etc.).We can thus understand the formal object of emotion as its essential intentionality - the kind of object (event, person, state of affairs) to which it must be directed if it is to be that emotion. However, the concept of intentionality has also been the object of philosophical debate for some time - despite its appeal as a way of understanding the nature of perception and other mental "acts." Most troubling is the obvious fact that emotions may be about nonexistent, merely imagined things.

Philosophers have also been concerned with the "why?" of emotions: their function and their explanation. With regard to particular instances of emotion, such as anger, these seem to be subject to two sorts of explanation. On one hand, they are seen as intentional, involving beliefs, desires, needs and values, and require an explanation that invokes a person's beliefs and attitudes towards the world (e.g. the belief that one has been wronged by another). However, this cannot be a complete account, when we consider non-cognitive factors such as sleeplessness, illness, and/or use of medication.

Given these multiple influences, how are we to consistently reconcile direct, underlying causation with an explanation in terms of beliefs, attitudes and intentionality? Many philosophers have attempted to get past these inconsistencies by emphasizing the importance of one form of explanation over the other, or to somehow reduce all explanations to one or the other.

The cognitive basis of emotion also raises another question: the rationality of emotions. While many philosophers have written as if the emotions were irrational (e.g. accounts of emotions as mere feelings or physiological processes), the fact that some have written of the emotions in terms of cognitions means that they can be evaluated in terms of the same epistemic and ethical criteria that we use to evaluate beliefs and intentions. Are they appropriate in the context? Do they consider the facts of the matter? Are their perceptions fair and their evaluations reasonable? Indeed, the argument is now prevalent that emotions cannot be understood without grasping their reasons, and these reasons, in turn, give us a basis for evaluation.

The rationality of emotions also moves to center stage the question of emotions and ethics that have been closely tied throughout philosophical history. How is it that emotion enters into ethical understanding? How do our ethics affect our emotions? While some would argue that emotions, beliefs and ethics offer no basis for ethics as they vary by culture, as does the human brain (which varies significantly with experience from person to person); neither is it so obvious that emotions differ that much from place to place (or person to person) either.

Finally, this brings us to the issue of emotions and choice. Some would argue that emotions are something that "happen" to us outside of our conscious control. On the other hand, Sartre suggests that emotions are willful. Most philosophers do not stake out such extreme positions, but we are still left to consider whether we are simply at the mercy of our emotions, or whether we may cultivate and "do" them in one way or another. Obviously, a great deal of ethics and our attitudes towards ourselves depend on this.

In the end, the philosophical study of emotion cannot be a detached and marginal discipline, but constitutes the very core of our inquiry into ourselves and our own natures. It was Socrates who said that "the unexamined life is not worth living" and who took as his motto "know thyself." For philosophers, part of that knowledge must reflect an understanding and appreciation of our emotions - which underlie much of what makes life worth living.