-To act rationally, is nothing else (III. iii. and Def. ii.) but to perform those actions, which follow from the necessity, of our nature considered in itself alone.
Arrazoiaren arabera ihardutea, hau baizik ez da (3. Zat., 3. Prop. eta 2. Def. arab.) gure izaeraren ezinbestekotasunetik bere baitan soilik harturik datozen ekintzak egitea.