Although ideally one should study Torah only for the sake of the mitzva, this does not mitigate his obligation to study Torah even if his motives are not pure. The Sages disagree concerning who is worthy of studying Torah: Is it only those who are wise and of distinguished lineage, or should it be available even to people of more modest lineage?

Rav Yehuda said that Rav said: A person should always engage in Torah study and mitzvot even not for their own sake, as through their performance not for their own sake, one comes to perform them for their own sake.

Beit Shammai say: One should teach only a person who is wise, humble, of distinguished lineage, and wealthy. Beit Hillel say: One should teach any person, as there were many transgressors in Israel who were drawn to Torah study and they became righteous, pious, and decent individuals. (Nazir 23b; Avot deRabbi Natan, version A, chap. 2)