The main purpose of this paper is to examine Roger de Piles' Conversations (1677), not only as the consistent theory of paintings, but also as a story, where the characters communicate with each other, looking for some steady grounds for consensus of their tastes. In the first part of Conversations, three characters discuss the proper taste and correct judgement on paintings. Pamphile, the instructor, firstly shows that, in order to obtain sane judgement, it is necessary to argue about various paintings with others, but at the same time not to accept their opinions without the conviction that they are reasonable. However, there is no further explanation of this seemingly important concept, "reasonable" in the whole book. Instead of such detailed explanation, Pamphile affirms that one has to build his taste on the basis of the Antique works' taste which is amended by Nature. Three additional characters in the second part, that is, Caliste, Leonidas, and Philarque respectively can be considered as advocates of the Antique works, Nature, and the Antique works amended by Nature. Here, de Piles do not ask whether each kinds of taste is fundamentally reasonable or not, but depict Caliste as a failure in this honnete conversation.