Aquinas thought that practical reason, through reflection on human nature, can determine primary moral principles (which he called the 'Primary Precepts'). Our 'conscience' then derives secondary principles ('Secondary Precepts') which are applied. As we practice balancing our needs against the needs of others, we develop Prudence.
synderesis - an innate knowledge of human nature and primary precepts through practical reason
conscientia - deriving secondary precepts, and applying them
prudence - the virtue…