Verb
(idiomatic) To permit events to proceed or a situation to develop without intervention or interference.
(idiomatic, euphemistic) To allow a person or animal to die without medical or other attempts to forestall death.
let Nature take its course (third-person singular simple present lets Nature take its course, present participle letting Nature take its course, simple past and past participle let Nature take its course)
Alternative form of let nature take its course
While day by day the overzealous student stores up facts for future use, he who has learned to trust nature finds need for ever fewer external directions. He will discard formula after formula, until he reaches the conclusion: Let nature take its course. Larry Bird
I guess they just took it for granted that that was what I was interested in and let nature take its course. Clyde Tombaugh