Newton's First Law: Text, Translations, Interpretations and Physics Education

The translation from Latin of Newton's First Law (NFL) was considered in a historical perspective. The study showed that Newton's original yields two versions of complementary meanings, one temporal and the other quantitative. The latter is especially important in presenting the idea of inertia of massive bodies, and a new paradigm of understanding motion. The presentation of NFL in physics textbooks was reviewed and a decline in the status of NFL in the physics curriculum was noted. As a rule, if quoted at all, NFL is presented in its temporal form, while the quantitative form does not appear. Normally, NFL is interpreted as a special case: a trivial deduction from Newton's Second Law. Some advanced textbooks replace NFL by a modernized claim, which abandons its original meaning. We advocate the importance and nontrivial meaning of NFL, and call for its `rehabilitation' in physics instruction within the discourse mode of education.