The basic tenet underlying all of Buber's philosophy is the contention that man has two modes available to him through which he can engage the world. The first mode (the mode of I–It) is the mode of experience. In experience, we engaging the world as an objective observer rather than as a participant, and we gather data through the senses and organize that data in such a way that it can be utilized by reason. Experience is the mode of science and philosophy, the mode through which we come to know things intellectually, and to put things to use for us. Western culture, Buber claims, has generally come to think that this is the only mode available to human beings for engaging the world. We tend to ignore the other mode, which is more vital to our existence as human beings.
This second mode that we often ignore is what he calls the mode of "encounter". In encounter (the mode of I–You), we participate in a relationship with the object encountered. Both the encountering I and the encountered You are transformed by the relation between them. Whereas experience is entered into with only part of one's self (the data-collecting, analyzing, theorizing part), one enters encounter with one's whole self. Whereas experience involves distance between the I and the It (i.e. the distance between subject and object) relation involves no such distance. And whereas the I of experience views the It only as a collection of qualities and quantities, the I of encounter sees the You as much more than that; the I of encounter sees the entire world through the You for as long as the encounter lasts.
Most encounters, unfortunately, cannot last very long. Encounters with inanimate objects of nature, with animals, and with other human beings are necessarily fleeting. Eventually we come to reflect on the You, to see it for its various qualities, to analyze it. Once we do this, the You dissolves into an It, and we are back in the realm of experience. It is only encounter with the eternal You, God, that is lasting and ultimately fulfilling.
Though Buber's aim is to get us to recognize that the mode of encounter is available to us and to help us open ourselves up to it, he does not believe that we should ignore the mode of experience. The mode of experience is necessary to our survival. It is through experience that we come to see an order in the world which we then use to obtain the necessary elements of survival. The realm of science cannot be discarded; but it is also not sufficient for our existence as human beings.
Our need for encounter, or relation, Buber claims, can be traced back to our prenatal state. When we are inside our mother's womb we are in a state of pure natural relation. There is perfect reciprocity between the womb and the baby, a flowing in and out of vital elements. Further, the womb is the entire universe for the fetus. Once we are thrust outside of the womb, we immediately begin to yearn for another such relation—not necessarily for a relation just like the one in the womb, but a relation similarly immediate and all-encompassing. Instead of a pure natural association (a physical one) we yearn for a pure spiritual association. This yearning, present in us from birth, is what Buber calls the innate or inborn You. It is a desire to enter into relation, to say "You" to someone or something.
We can actually observe this inborn You, Buber tells us, by watching a developing child. A newborn baby is clearly only interested in relating, rather than in experiencing. The baby reaches his hands out even when he does not want anything such as food or comfort, he stares hard, he "talks" when no one is around to listen. These gestures cannot possibly be attempts to acquire, or to possess, since they do not aim at acquiring or possessing anything. Instead, they are attempts to relate. Encounter, then, the mode that we currently all but ignore, is actually the primary human state. Experience only comes later.
The progression from a state of pure relation, to one of experience goes as follows: First the baby only relates. The baby is so immersed in relation that he does not even have any awareness of an I separate from a You. There is only the relation for him. Slowly, though, he begins to get the sense of an I, some constant that is present through all relations. Once he has developed I–consciousness, the baby can begin to experience the world. From the notion that there is an I he forms the notion that this I can be separated from things, and thus forms the notion of It, something separate, divided, something that can be utilized and analyzed and known.
In the second part of the book, Buber turns from the individual human psyche to modern society. Modern society, he tells us, is an It-world. All of our institutions—our governments, our economic systems, our schools, often even our marriages and other personal relations, our very feelings—are built up out of I–It rather than I–You relationships. In politics, for instance, the leaders see their constituents as Its to be utilized, as things with certain desires and needs and with certain things to offer. Similarly, the constituents see their leaders as Its who can offer them possible services. As the current system stands, neither can possibly see the other as a You; it would, in fact, destroy the system. The same could be said for our economic system, and most of our other institutions.
It is because our world is an It-world, Buber tells us, that modern man suffers from so much existential angst. Trapped in this It-world, man feels that life is meaningless. He feels that he is eternally caught in the gears of forces beyond his control, in the vast, uncaring, inexorable mechanisms of history, psychology, sociology, and physics. Even though man enters the realm of experience in order to master objects, nature, and other people, when man is caught exclusively in an It-world, he comes to feel helpless and lost (though these unsettling sentiments, Buber is quick to add, often only come bubbling up in weak moments, perhaps late at night in the grip of sleeplessness).
The cure for our modern affliction of alienation and meaninglessness would be to open ourselves up to encounter, in particular to open ourselves up for encounter with the eternal You, God. We glimpse the possibility of encountering God through all of our other encounters which are fleeting and do not satisfy our desire for relation. In each of these fleeting encounters, we glimpse that there is something more possible, an absolute relation that is not transient. This permanent relation is that with God.
In order to encounter God, one must ready one's soul. Once the soul is ready for this encounter, it will inevitably occur. The way to get ready for encounter with God is primarily to want with all of one's being to encounter God. In addition, one must 'concentrate one's soul.' In concentrating the soul, man brings together all of his contradictory parts of his personality and existence and holds them together as a unity. He holds together, for example, the I of experience and the I of encounter.
This process of readying oneself is obviously not passive, but requires an active decision: you must decide that you want to encounter God and you must actively take steps to concentrate your soul. Buber calls this decision 'man's decisive moment.' The decision to enter the absolute relation is not an easy one. To leave behind the world of experience is terrifying because the world of experience is predictable, understandable, and easily manipulated, while the world of encounter is none of these things. In order to ready oneself for encounter, then, one must also shed one's drive toward self-affirmation, the drive toward self-protection and the need to feel that you are in complete control of yourself and the world around you.
The only way to know that encounter with the eternal You has occurred is through the results of this encounter. The encounter transforms you, turning you into someone who sees every other being as a You. Man comes out of the absolute relation feeling a sense of loving responsibility for the entire course of the world. He cares about everyone and everything, because he loves everyone and everything. The entire world is a You to him. This transformation is divine revelation.
Ideal society, community, is formed by a group of people who are in relation with the eternal You (the relation to the eternal You never really ceases, it continues to exist forever in the form of the actions which it caused). These people can all say "You" to the entire world. Their community is based on the common relationship they all hold to the eternal You, the relationship that has transformed them into people who live their lives by encountering. It is through the building of such a community that religion is actualized, and God brought down into the world. In such a community, everyday life is holy.
Relations are not either / or, but varry in degree. The closer one comes to a genuine I-You relationship, the more likely one is drawn to service, and increasing I-You relationships.