The Commens Dictionary

Quote from ‘The Basis of Pragmaticism’

Take any proposition and erase certain parts of it, so that it is no longer a proposition but only a blank form which after every blank had been filled by a proper name would become a proposition, however nonsensical. Such a blank form of proposition which can be converted into a proposition by filling every blank with a proper name has been called by the writer a rheme. There may be any integer non-negative number of blanks, so that the term rheme is extended even to a full proposition, when it is looked upon as having a number of blanks which happens to be zero