What is it that allows some of us to be hopeful in a world full of tragedy and injustice, where time and chance have their way with everyone, and where we face defeat in the end? Apart from a comforting religious faith it requires some trick of the mind to be able to derive pleasure and significance from the moment. Not everyone can do it. The lifetime prevalence of depression in the population has been estimated at 15-20%, while at any given moment around 10% of us are so beset by sadness and loss of personal significance that we qualify for a formal diagnosis of depression

    Given the state of the world it is hardly surprising that many people harbor doubts about the future. Pessimists, those most prone to depression, almost invariably consider themselves "realists," and watching the news it's hard to argue against the proposition that things are bad and getting worse. And yet our individual happiness in the present moment is largely dependent on what we anticipate. Our beliefs about the future constitute self-fulfilling prophesies: we get not what we deserve but what we expect. This truth can be seen most vividly in our interactions with other people. Those we approach with trust and openness tend to respond helpfully. Conversely, if we treat people with suspicion, they are likely to reciprocate.

    To be hopeful is not unselfish. On the contrary it is in our self-interest to risk the occasional disappointment that optimism implies in order to benefit from the more frequent experience of realized hopes. The habitual mask of the pessimist is similar to that of the depressive: a fixed frown of discontent and unhappiness. In fact, the triad of perfectionism, pessimism, and discouragement is a familiar precursor to and accompaniment of clinical depression. The logic is unavoidable: those who demand too much of themselves and others are bound to be unhappy in an imperfect world. Like most emotions （anger, anxiety, love）, unhappiness is contagious; it feeds on itself and demands to be shared. There is a story of two girls assigned to clean a stable. One focuses on the material she is shoveling, the other thinks that, "There must be a pony around here somewhere."

    To some extent hope or the lack of it is, like many of our attitudes, a product of our experience. There is an area of psychology called "learned helplessness" that concerns itself with the consequences to people when they conclude that they have little choice in what happens to them. If we assume that our efforts are unrelated to the outcomes in our lives we develop an outlook of pessimism and passivity. Optimism requires that we believe that we can favorably influence our fates.

    How we react to setbacks in our lives is a particularly good test of how hopeful we are. If we see some bad outcomes as being inevitable in a world in which our control is limited, we can nevertheless retain our confidence in our ability to change things for the better. If we react to adverse events by feeling discouraged and powerless and engage in a process of self-blame, we are unlikely to imagine that we can improve the situation. Eventually, our skepticism about changing things for the better hardens into an habitual attitude. Or as one bookstore visitor said, "I almost bought a book about how to think positively, but then I thought, 'What good would that do?'"

    It usually doesn't take long to find out whether you are in the presence of an optimist or pessimist. One of the best indicators of how someone else is feeling is the mood they evoke in us. If being around another person causes us to feel discouraged, it is a fair bet that this is, at least in part, a reflection of their outlook. Conversely, optimism is also transmittable. Sometimes this takes the form of a reinterpretation of events. Recently I was on a tour bus whose driver was the recipient of the truck driver's salute from an irritated motorist. Rather than express anger or insult, the driver suggested, "Look. That guy thinks I'm number one." As with all of life's adversities a working sense of humor is an invaluable defense. The situation may be critical but not serious.

    Optimism is highly correlated with success. What do you suppose a major league hitter is telling himself before he bats? Even the best of them make an out two-thirds of the time. Do you suppose that this statistic is weighing on him as he approaches the plate? Or is he likely to be imagining a happier result. People who never developed a belief in themselves, no matter their intrinsic talent, are unlikely to appear on major league rosters; they have long since been encouraged to pursue other occupations. The same might be said of successful salespeople. There is also a role here for recognizing that, since our pasts are largely stories of our own creation, we have the power of selective recall. Optimists are more likely to remember good outcomes while pessimists are discouraged by memories of failure. Optimists are also skilled at using the psychological defense of "reinterpretation" of events.

    On a hot day many years ago my the-middle school daughter Emily, one of the most optimistic people I know, was paddling with me in a cardboard boat race. As we began to take on water and the boat dissolved beneath us, I thought of the hours I had spent sealing and painting the fragile craft to prevent this outcome. Finally it sank and we became swimmers. Emily, seeing my disgust, said to me, "Oh Dad, doesn't that cool water feel good?"

    The school of "positive psychology" has demonstrated that optimism, like helplessness, can be learned. Using cognitive techniques and stress management Martin Seligman and his colleagues at the University of Pennsylvania have shown conclusively that pessimists can be taught to be optimists with beneficial effects on school and occupational success, even health.

    In one of the frequent examples of overlap between virtues, optimism is heavily dependent upon courage. Pessimism, like depression, is a "safe" position. Pessimists may be discouraged but they are seldom disappointed. If situations turn out badly, they expected as much. If things go better than predicted, they can only be pleasantly surprised. Optimists, on the other hand, risk disappointment, or worse yet, being taken advantage of and looking foolish. This is why we seek the middle ground, presumably occupied by true realists. Since we lack the power of foresight, however, we are all subject to surprise. So who would you rather spend your life with: those who brace themselves for the worst or those who anticipate the best?

    在我們這個充滿了災難和不公，時間與機會因人而異，且眾生終將面臨毀滅的世界上，是什么令一些人懷抱希望？除了慰藉性的宗教信仰，這種心態需要些許能從當下汲取愉悅與意義的心靈技巧。并非人人能為之。抑郁癥在一生中的發生率約占人群的15-20%,而在任一時刻，我們當中約10%的人被悲傷和個人意義之喪失所困擾--這種情形將可以被我們正式確診為抑郁癥。

    既知天下之情形，又豈會驚訝于那么多人對未來抱有疑惑。最傾向于抑郁的悲觀者們，大抵總是將自己視作"現實主義者";事情很糟，并越來越糟--看新聞時很難駁斥這種觀點。可我們當下的個人幸福卻大大地依賴于我們的期待。我們對未來的信念構成了自主履行的"預言":我們所獲得的不是應得的，而是欲得的。這一事實最能生動地表現在我們與他者的交往中。那些我們帶著信任與坦誠接近的人，往往會報之以李。反之，若我們以猜疑待人，他們也可能以牙還牙。

    懷抱希望絕非無私。相反，它是帶著我們的私心，到樂觀主義所謂"偶然的失望"中去冒險，從而讓自己更頻繁地在領悟希望之體驗中受益。悲觀者那慣常的面孔，好似一張抑郁的臉：總是掛著不滿和不悅的蹙額。事實上，完美、悲觀和灰心這三者，乃臨床抑郁癥之先兆及伴隨癥兆。這種邏輯在所難免：對自己及他者要求甚蕃者，勢必在不完美的世界里感到不悅。正如大多數情緒（憤怒，焦慮，愛戀）一般，不悅亦會傳染；它自我壯大并欲求共享。從前有兩個女生被指派去打掃馬廄，一人關注于她在鏟的東西，另一人思忖道，"附近一定有匹小馬。"

    在一定程度上，希望或缺乏希望，就像我們的很多態度一樣，都是我們的經驗之產物。心理學中有一個喚作"習得性無助"的領域，研究人們認為自己對所處境況無助時的后果。如果我們假設自己的付出與成果無關，那么我們就衍生出悲觀和被動的觀念。樂觀要求我們相信：自己確能影響自己的命運。

    我們怎樣應對生活中的挫敗，很能測出我們懷抱怎樣的希望。假如我們把一些惡果，視作人類愛莫能助的世界中之必然，我們還是能對自己將事情變好的能力保留信心。假如我們對不利事件反應為氣餒無助和自責，那么很難想像我們還能改善境況。最終，我們那對改善事物的懷疑觀固化為慣常的態度。或者如一位書店顧客所言，"我常常購買如何積極思考的書籍，而我后來想道，'它能起到什么作用？'"

    通常，要覺察出你面臨的是一位悲觀者還是樂觀者，用不了多長時間。他人感受如何的最佳指示劑之一，是讓我們喚起的心情。如果和一個人在一塊兒，使我們感到氣餒，那么可以公正地說，至少這是他們觀點的部分折射。反之，樂觀亦會傳播。樂觀有時需要對事件進行重新解釋。最近，我坐旅行車，開車的司機就能接受一位脾氣火爆的卡車司機的不敬。沒有表達憤怒或侮辱，司機說道，"看。那家伙覺得我是第一。"面對一切生活中的不幸，足夠的幽默感是無價的防御工事。事情也許很重要，但不嚴重。

    樂觀與成功有高相關。你對棒球聯合總會球員期待了什么，是不是在他擊球前就告訴他了？即使是他們當中最佳的也有三分之二的出局。你覺得這個統計數據會讓球員在接近本壘板時感到有壓力嗎？或許球員會憧憬一個更加的結果。那些從未對自己培養出一套信仰的人，無論其秉賦如何，不可能登上棒球聯合總會的花名冊；他們被鼓勵去做別的事兒已久矣。成功的售貨員大致是相同的。我們還要承認一個角色，由于我們的過往極大地編織了我們自己的世界，我們便擁有選擇性回憶的權利。樂觀者更喜歡憶起好的結果，而悲觀者則被失敗的記憶搞得氣餒。樂觀者長于使用對事件"重新解釋"的心理防御。

    數年前一個炎熱的日子里，我那上中學的十歲女兒艾米麗--我所認識的最樂觀的人之一，和我在紙皮箱舟賽中劃船。我們一上水面，小船就在我們身下分開了。我還能記得，為了預防這種狀況，我曾花了數小時來密封和涂繪小船。最后它沉了，我們成了游泳賽手。艾米麗，看出我的厭煩，對我說，"喔，爸爸，那么棒的水不好嗎？"

    "積極心理學"一派業已展現了樂觀--正如無助感--是能夠習得的。賓夕法尼亞大學的馬汀·瑟李格曼（Martin Seligman）與其同事證實道，使用認知技巧和壓力管理法，悲觀者能夠被訓育為樂觀者，益于學業和職業成就，甚至健康。

    在諸美德重疊的常見例子之一中，樂觀很重地依賴于勇氣。悲觀，如同抑郁，是一席"安全"之地。悲觀者也許氣餒，但他們罕少失望。如果情況惡化，他們期待如此。如果事情優于預期，他們僅可能愜意一驚。樂觀者，相反地，冒著失望或更嚴重的險，甚至被別人利用、視為夯貨。這正是為何我們尋找中間組，他們大致是真正的現實主義者人群。我們固然缺乏預見力，但我們都會驚訝。那么，你更愿意與誰共度一生：是那些將自己束縛于致惡的人？還是那些期望最佳的人？