Fear and Trembling opens with a preface by the pseudonymous author, Johannes de Silentio, which discusses the modern world's cavalier attitude toward doubt and faith. Today, he suggests, everyone is unwilling to stop with doubt, but wants to go further, as if doubt itself were something easily attained. Descartes attained doubt, but only by means of a long and difficult process following years of study. The Greek skeptics considered doubt to be a matter that takes a lifetime to acquire. People today want to start at this point, the point Descartes attained only by denying himself everything.

Today, he suggests further, everyone is unwilling to stop with faith, but wants to go further, as if faith itself were something easily attained. Faith was once considered a task for a lifetime, but today, all people seem to assume they have it, since they all seem to want to go further.

Johannes confesses that he is not a philosopher, that he does not understand the system. He points out that even if faith were put into conceptual form, the system could not help us understand it, how it comes to us, or how we come to it. Johannes is not tied to the system in any way, but writes, he suggests, because writing to him is a luxury, the more so the fewer readers he has. He imagines he'll be ignored, and that what few critics write about him will disdain him. What he fears even more is that someone will attempt to make sense of his writing by carefully dissecting and systematizing it. Johannes pleads with this "enterprising abstracter": this is not the system, nor can it be divided up in such a clinical manner.

All of Kierkegaard's major philosophical works are written pseudonymously, with authorial personas such as "Vigilius Haufniensus," "Johannes Climacus," and "Constantin Constantius." Fear and Trembling is the only book authored by Johannes de Silentio, which literally means "John of Silence." Alastair Hannay identifies the name as a reference to a character of that name in the Grimm fairy tale "The Faithful Servant." That John was the servant to a young king, and warned his master of three dangers, knowing full well that he would be turned to stone for having spoken. Later, the king sacrificed his two sons in order to bring John back to life, and once restored, John resurrected the two sacrificed sons.

We may interpret the name and the allusion Kierkegaard has chosen on a number of levels. Most immediately, the name connects with what the author has to say about faith. This will be discussed in greater detail in later stages of this commentary, but briefly, faith is regarded as something that cannot be intelligibly explained, understood, or spoken about. Johannes is a very talkative, eloquent author, and yet he is "of silence" because the one subject he most wants to discuss--faith--is beyond the power of his words.

The John of Silence from the fairy tale can also connect to our author in two ways. The first we see in the preface, as Johannes suggests that his writings are likely to be met with critical disdain or incomprehension, if they are to be met at all. Like the character in the fairy tale, he speaks the truth and warns against the complacency of the age, and is likely to be rewarded with deadening silence. This prediction is somewhat prophetic--Kierkegaard was largely ignored, and reviled when not ignored, during his lifetime. His fame would not come until the twentieth century, long after his death. We also see in the fairy tale the theme of repetition emerging, where the young king can regain his sons after having sacrificed them.

The discussion in the preface of doubt and faith are meant as a direct critique of the Hegelian "system" that dominated the philosophy of the day. For Hegel, faith is lower than reason since it is immediate and requires no reflection at all. Faith is then something that we must move beyond, according to Hegel, if we are to understand the world correctly. Similarly, doubt is associated with Descartes by the Hegelians, and is considered an earlier stage in the dialectical process that leads to the Hegelian system. This doubt is a starting point that must also be moved beyond.

Johannes contrasts the easy intellectualizing of the Hegelians with the dedication required by true doubters and believers. The ancient skeptics, for instance, maintained that since nothing is certain, they should suspend judgment about everything. Learning to suspend judgment took a lifetime of dedicated asceticism, however, since we are naturally accustomed to passing judgments on the things we sense and think about. Similarly, the faith required of Abraham was not a simple matter to be had and then moved beyond. Abraham's faith had to be so strong that he would unquestioningly sacrifice his only son to God.

The difference between these people and the Hegelians can be understood as the distinction between knowing with one's mind and knowing with one's heart. We might draw the analogy to our consciousness of death. We all know that we will die, but young people tend only to know this with our minds: we know it as a fact, and we would never deny it. However, only old people, or those who have had a near-death experience, might know with their heart that they are going to die. That is, they are conscious of their mortality in a way that informs their daily actions and their attitude toward life.

Johannes sees this contrast as one between reflection and passion. The Hegelians may think they have reasoned through faith and doubt in the same way that think their system allows them to reason through everything else. However, faith and doubt, unlike science or logic, are meaningless and void without passion. We cannot allow Descartes to do our doubting for us: in order to appreciate what it means to doubt, we need to go through the process ourselves. Anything less will lead to cheap theorizing that doesn't understand the objects of its theories. By rationalizing doubt and faith, by rendering them as parts of a system built fully by reflection, Hegelians have destroyed doubt and faith, have rendered them impotent. Kierkegaard is a staunch opponent of the Danish church of his day, feeling that faith has been reduced to an aesthetic level which cheapens the true value of religious passion.