Most people are servants of their passions, but the truly free person is the one who can control his desires. When the sages taught "Only one involved in Torah is truly free" (Pirkei Avos 6:2), they meant to say that only Torah allows one to free himself from the shackles of desire and to truly exercise free choice. Without Torah, one is not free at all, he is a slave, controlled by a master foreign to his better instincts. While intellectually he might have correct ideas of how to live, ultimately his master - his passion - will force him to act otherwise.

Excerpt from: The Torah Treasury pg. 146