I am a japanese rinzai zen buddhist priest and scholar on Zen thought. I live in a small Zen temple in the countryside of Shiga Prefecture, the province next to Kyoto. My prefecture is well known, because it is near the biggest lake in Japan, called Biwa-ko, where the ninth International Conference of the Lake and Marsh was held in 2001.

Looking at the boundless space through a window on a plane from Japan to America recently, I was thinking of the smallness of a human existence, which lasts only for a number of decades and soon passes away without knowing anything about this infinite universe. Such a short lifespan is still comfortable for humans, as long as we enjoy our lives creatively and through art. As part of this task, religion and science each have been a driving force expanding the human desire for creativity throughout history.

Toward the end of the last century, the well-known historian Arnold Toynbee summarized the twentieth century as a "century of rapid advancement of natural science, and creative encounter of world religions." But Toynbee's admiration of the brilliant advancements of the twentieth century does not seem to be universally true. Human beings are now faced with a potential turning point in scientific progress, where scientific advances raise as many questions as they resolve.

The twenty-first century does not need to be, nor can it be, just an age of further steps in human technological achievement. It needs to be a century in which human beings stop their headlong rush ahead, plant their feet firmly, and, as an ancient Chinese proverb wisely says, "Stop walking to return to one's Self " (Taiho shūko, in Japanese). I firmly believe, therefore, that the twenty-first century should be a "century of deep considering." As Heidegger points out, human beings in our time truly seem to be running away from deep thinking, which is the essential nature of human existence. To reverse this tendency, some people want to recover what is missing in their thinking, to recover Heidegger's reflective thinking. Thus, they occasionally turn their gaze toward Buddhism, which teaches us to have a "right view" in order to investigate the reality of the world. In order to investigate this path toward right thinking, I shall begin with the most fundamental teaching of the Buddha, who taught the following in his "First Speech" to his five followers right after his Great Awareness of Reality, recorded in the Dhammacakkapavattana Sutta:

The world is full of suffering. Birth is suffering, old age is suffering, sickness and death are suffering, sorrow and lamentation, pain, grief, and despair are suffering. To meet a man whom one hates is suffering, to be separated from a beloved one is suffering, to be vainly struggling to satisfy one's need is suffering. In fact, life that is not free from desire and passion is always involved with distress. This is called the Truth of Suffering. . . .

In order to enter into a state where there is no desire and no suffering, one must follow a certain path. The stages of this Noble Eightfold Path are right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration. This is called the Noble Truth of the Path Leading to the Cessation of Suffering.

Among these practices, right investigation through right concentration would be the most necessary to the contemporary human being, who constantly forgets to stop walking in order to watch a thing carefully, patiently. "To think" is a fundamental condition of man's existence: cogito ergo sum, as the French philosopher Descartes said. To think does not require any specific religious belief, but it does belong to each person as his or her ability.

Furthermore, it is the Buddha who followed such a human ability and pursued its implications for one's life. Through his deep thinking under the Bodhi tree, he discovered the root of human existence that is suffering (dukkha) and also recognized the root of suffering that is ignorance (avidyā).

Human beings today have begun to be aware of the reality of human suffering, but we are still not aware of how to think deeply about such a situation. Shin'ichi Hisamatsu, a leading Zen scholar of the Kyoto School, who was my teacher and a guiding influence during my college life, wrote:

The inner structure of humankind itself is based upon Antinomy. This is the core reason why humankind cannot overcome this limit or destiny by itself. . . . It is an authentic way of knowing the limit of humankind, that we be aware of ourselves as limited beings. Therefore, it is a matter of ignorance that we do not know of the limit of our existence. In this sense modern humankind is like the ignorant who is not aware of his own limits.¹

Hisamatsu's indication reminds me of a saying of Kierkegaard's that "to be able to despair is a strong point of man." In Zen Buddhism, a master brings his disciple to great doubt or despair by refusing his questions and pushing him back onto himself instead. In this way, the disciple loses his ordinary self-ego. This state of non-self or unconscious self is a necessary precondition for finding an absolute self existing beyond the ordinary self. Unless humans break through this great mass of doubt, they will never be able to reach their final freedom.