Morphemes and Lexemes versus “ Morphemes or Lexemes ? ”

More than a century after the first linguistic definition of the notion of morpheme by Baudoin de Courtenay (1895) and Sweet (1876), an ever-lasting debate – which I shall refer here as the “Morpheme or Lexeme” (M or L) debate – on the nature of linguistic bricks is still going on. Since a by-product of this debate is terminological confusion in the use of the four notions of morpheme, lexeme, word and item, I shall start by describing very briefly the conflicting uses of these terms and then show that to accounting for the generation of the lexicon, i.e. of both new senses and new lexical units, requires accepting the co-existence of two distinct semantic stocks and explaining how morphemes which belong to the first stock may become lexemes or be involved in lexeme-formation processes.