The paper aims to show how in practice the requirement to maintain the coherence of the system of beliefs and the corresponding behavior of «spontaneous beliefs» within the concept of empirical knowledge by L. Bonjour can be correlated. The main example considered is P. Kosso’s arguments about the reliability of Thucydides’ «History» connected with the idea of possibility of justification restricted to a single source of evidence. As a heuristics we deal with the problem of how to establish the contextual dependence of inference and, in general, of the structure of the justification of knowledge within the given situation. First, it is possible to extend L. Bonjour’s concept with the idea of the nonmonotonic nature of justification and coherence of the original system of beliefs. Such a step, in particular, will make it possible to abandon the need for the argument «from meta-justification». Second, the interpretation of «spontaneous beliefs», their justification and facts fixing whether these beliefs violate the coherence of the original system or not, as patterns (in the sense of the fundamental concept of existence by D. Ross) makes it possible (for example, due to the exact understanding of «interpretative perspective» and «functional role» of the projection) to meaningfully interpret the «context dependence» in each particular case.