The Golden Rule
The crown jewel of the yamas, or moral tenets of yogic philosophy, is that of ahimsa, or non-violence. All other yamas and niyamas find their roots in the soil of ahimsa, since nonviolence informs the ways in which those guidelines manifest. For example, satya, or truth-telling, could easily become a way to kick people when they are down if not applied with a heavy dose of ahimsa through consideration of timing, and whether or not your truthful words need to be said aloud at all.