leave to own devices
leave (one) to (one's) own devices
To let one rely on oneself, without any help or other interference. I'm going to leave you to your own devices and see what you come up with without my input. It's amazing how some kids can really thrive when you leave them to their own devices, while others will be completely helpless.
leave to (one's) own devices
1. To allow (someone) to do as he or she pleases: left the child to her own devices for an hour.
2. To force (someone) to cope or manage without assistance: Most people would die in the desert if left to their own devices.