This article focuses on the emergence and use of the evidential particle de(i) in the history of Russian. In Old and Middle Russian de(i) was used as a quotative clitic, which was initially an adverbal marker of another’s perspective and later marked the other’s utterances in asyndetic constructions, where, however, it became non-obligatory. Traditionally, the particle was used for quoting juridical documents or retelling court proceedings, and it was current from the 15th until the end of the 18th century. From the end of the 17th century the particle de(i) acquired modal semantics, and in parallel with the particles jakoby and budto expressed disapproval of the quoted opponent and, in particular, of his utterances. This usage of de(i)was especially characteristic of journalistic texts of the 18th century, and this is still the main domain of its usage in Modern Russian. Thus, the semantics of the particle de(i) developed from the neutral quotation of another’s utterances to the polemical marking of the other’s point of view. The non-obligatory usage of the particle to distinguish the utterances of self vs. other was a prerequisite for the development of this modal meaning.