by Kierkegaard is often thought of as a theologian rather than a philosopher. Yet Kierkegaard referred to himself as a “philosopher” in a letter to his friend Rasmus Nielsen (see Letters and Documents, no. 228). Nielsen was himself a professor of philosophy at the University of Copenhagen, so Kierkegaard must have had a fairly high opinion of his own analytical powers to identify himself in this way to his friend. Kierkegaard studied theology, but he also studied philosophy, hence his epistemology is extraordinarily sophisticated.
One of the biggest obstacles to understanding Kierkegaard’s epistemology is that few Kierkegaard scholars outside Denmark read Danish. This situation is exacerbated by the fact that most Danish Kierkegaard scholars are theologians rather than philosophers, so while they cannot help but have an interest in Kierkegaard’s epistemology in that it is essentially tied up with his views on faith, they often lack the theoretical background and analytical training necessary to undertake serious scrutiny of it.
As if these obstacles were not enough, Kierkegaard displays a general disdain for terminological consistency for its own sake. “Part of the difficulty with trying to understand Kierkegaard’s epistemology,” I explain in the introduction to Ways of Knowing, “thus concerns the fact that he makes no rigorous terminological distinctions among the various Danish expressions for knowledge” (15). That does not mean, however, that his thought was conceptually loose. It was not. What was important for Kierkegaard was not terminological consistency, but conceptual consistency. Lars Bejerholm explains in Meddelelsens Dialektik (the dialectic of communication) (Muksgaard, 1962) that
“the relation between a linguistic term and a concept, according to Kierkegaard, is usually such that the linguistic term denotes a concept. This concept may, however, be denoted by a variety of linguistic terms. It is, therefore, a matter of indifference which terms are used to denote a given concept. The most important thing, according to Kierkegaard, is that one ‘knows what one is talking about;’ the particular terms used are, in contrast, inessential.” (60 [Ways of Knowing, 16]).
Kierkegaard thus occasionally adapts his terminology to his audience, as is the case, for example, with his use of Erkjendelsen and Viden. Both can be translated as knowledge, but the former is an academic or technical expression whereas the latter is more colloquial.
One of the projects of Ways of Knowing is thus, as I explain in the introduction, to distinguish the different senses in which Kierkegaard uses various philosophical expressions and, in particular, the senses in which he uses the various expressions for knowledge.
I will have more posts in the future that relate to Kierkegaard’s epistemology and I welcome questions from readers on this topic.
Piety on Kierkegaard 
Serious writers often talk about the importance of finding precisely the right word to convey their meaning. Lawyers, too, quibble over the shadings of meanings of various terms for the “same” concepts. I’m surprised that a philosopher would not worry about such precision, although I can understand his desire to simplify concepts for general audiences. Einstein did that, too.
I think Kierkegaard was concerned that people got the concepts right and felt that playing around with the terminology was more likely to lead to the correct substantive understanding of what he was trying to communicate than was rigid technical terminology.