"Prayer is nothing else but the application of the heart to God, and the interior exercise of love. St Paul commands us to 'pray without ceasing'."
Jeanne Guyon or more fully, Madame Jeanne Marie Bouvier De La Motte Guyon, was imprisoned for 8 years due to the publication of this text.
All students of thought should get this historic book. This 1875 edition is provided in a slim volume with full text at an affordable price.