natural light

noun2

1. •
   Light as supplied by nature (nonmanmade light sources), such as (especially) the Sun or (sometimes) the Moon and the stars.

   • Continuous runs of patent glazing in the roof and walls, down to some 6 ft. above ground level, provide abundant natural light. — 1960
2. •
   (figurative, no longer used) Innate wisdom or knowledge.

   • ...unless we will wink against our own natural Light, we are without any further Scruple to acknowledge That God does exist. — 1662