from: http://tguild.oto.de/libri/hist_Kellner.html
The Spiritual Father of Ordo Templi Orientis was Carl Kellner (Renatus, Sept. 1, 1851 - June 7, 1905), a wealthy Austrian paper chemist. Kellner was a student of Freemasonry, Rosicrucianism and Eastern mysticism, and traveled extensively in Europe, America and Asia Minor. During his travels, he claims to have come into contact with three Adepts (a Sufi, Soliman ben Aifa, and two Hindu Tantrics, Bhima Sena Pratapa of Lahore and Sri Mahatma Agamya Paramahamsa), and an organization called the Hermetic Brotherhood of Light.
In 1885, Kellner met the Theosophical and Rosicrucian scholar, Dr. Franz Hartmann (1838 - 1912). He and Hartmann later collaborated on the development of the "ligno-sulphite" inhalation therapy for tuberculosis, which formed the basis of treatment at Hartmann's sanitarium near Saltzburg. During the course of his studies, Kellner believed that he had discovered a "Key" which offered a clear explanation of all the complex symbolism of Freemasonry, and, Kellner believed, opened the mysteries of Nature. Kellner developed a desire to form an Academia Masonica which would enable all Freemasons to become familiar with all existing Masonic degrees and systems.
Academia Masonica
In 1895, Kellner began to discuss his idea for founding an Academia Masonica with his associate Theodor Reuss (Merlin or Peregrinus, June 28, 1855 - Oct. 28, 1923). During these discussions, Kellner decided that the Academia Masonica should be called the "Oriental Templar Order." The occult inner circle of this Order (O.T.O. proper) would be organized parallel to the highest degrees of the Memphis and Mizraim Rites of Masonry, and would teach the esoteric Rosicrucian doctrines of the Hermetic Brotherhood of Light, and Kellner's "Key" to Masonic symbolism. Both men and women would be admitted at all levels to this Order, but possession of the various degrees of Craft and High-Grade Freemasonry would be a prerequisite for admission to the Inner Circle of O.T.O.
Unfortunately, due to the regulations of the established Grand Lodges which governed Regular Masonry, women could not be made Masons and would therefore be excluded by default from membership in the Oriental Templar Order. This may have been one of the reasons that Kellner and his associates resolved to obtain control over one of the many rites, or systems, of Masonry; to reform the system for the admission of women.
The discussions between Reuss and Kellner did not lead to any positive results at the time, because Reuss was very busy with a revival of the Order of Illuminati along with his associate Leopold Engel (1858-1931) of Dresden. Kellner did not approve of the revived Illuminati Order or of Engel. According to Reuss, upon his final separation with Engel in June of 1902, Kellner contacted him and the two agreed to proceed with the establishment of the Oriental Templar Order by seeking authorizations to work the various rites of high-grade Masonry. (from: http://tguild.oto.de/libri/hist_Kellner.html)
Franz Hartmann
“Mr. Keely is perfectly right in saying that 'all disease is a disturbance of the equilibrium between positive and negative forces'. In my opinion, no doctor ever cured any disease. All he can possibly do is to establish conditions under which the patient (or nature) may cure himself. The universal power which Mr. Keely calls the 'ether', and which Dr. Kellner calls the 'transitory element', was known to the mediaeval philosophers as prima materia, will and thought; or, according to Schopenhauer, will and imagination and substance. I recognise only one universal and fundamental power, which I call consciousness, acting within matter by means of thought; and I have no doubt that you already know that we agree all around, although we may not all use the same terms to signify the same objects. In your most important papers, I have found my own sentiments and views reflected; and I have in my books on 'Magic'. ' Paracelsus, and 'the Rosicrucians', attempted to explain these identical views. Why will our scientists insist on refusing to see the self-evident fact that all visible material substances, animal organs, etc., are nothing else than the ultimate products of pre-existing psychic (interior and invisible) forces? These facts were all known to the ancient philosophers; while the moderns insist on mistaking the effects for the cause. They reject the idea of God (the primordial cause of all in its highest aspect of spiritual consciousness) because they formed a misconception of that which is intellectually inconceivable; they found that God could not be that which they had imagined, and they logically (?) concluded that there could be no Divine power at all. But this subject is too grand, too sublime, and extensive to be more than alluded to in this letter, and I merely write these remarks to show you that your views, those of Mr. Keely, and my own are all identical, as they, indeed, must be with those who are capable to perceive self evident truth; for the truth is only one, and all who know it possess that same identical knowledge. Mr. Keely's power seems to be derived by changing the vibrations of cosmic ether. The machine which my friend Dr. Kellner has invented seems to be based upon the same principle, only, while Mr. Keely transforms these vibrations into some force connected with sound, Dr. Kellner's machine transforms them into electricityâ€. [Keelys Secrets - Part 2 - One Phase of Keelys Discovery in Its Relation to the Cure of Disease]
See Also
Etheric Force Identified as Dynaspheric Force mentions Kellner
Kellner - Electricity from Space
The Key to the Problems. - Keelys Secrets mentions Kellner