The idea of a 'secret' doctrine was not to shut people out.

Any discussion of the church's secret doctrines was offensive, she said.

I am not very certain of the secret doctrine of this sect in the matter.

The first fathers of the church made every effort to erase this secret doctrine from the memories of those who were familiar with it.

Upon hearing of the secret doctrine, Young recalled he "desired the grave, and I could hardly get over it for a long time."

He wanted to tell me about the secret doctrine and he couldn't do that in a restaurant with other people nearby who might overhear him.

The second were generally Masonic, though hinting at Pasqually's own secret doctrine.

Blavatsky wanted to publish a third and fourth volume of The Secret Doctrine.

Scriabin reread the "Secret Doctrine" very carefully and marked the most important places by a pencil.

A Brotherhood of Knights bound by secret doctrines and magical incantations?