Abstract: Chomsky-s linguistic naturalism occupies a central place in his linguistic theor y. According to him, language should be studied in the same way as we study natu ral objects, such as stars, plants, hearts, and eyes. His Universal Grammar has been developed on this basis. To justify his language naturalism, Chomsky puts f orward the so-called "Martian Argument". In the paper, I analyze Chomsky-s " Martian Argument", and I shall point out its problems. I shall argue that the a rgument does not give sufficient support to linguistic naturalism. I shall also present another approach to the study of language, based on Zellig Harris-s idea of "discovery procedures", and argue that it is advantageous over Chomsky-s U G.