- Mystic Christianity; Or, The Inner Teachings of the MasterAuthor: William Walker AtkinsonLanguage: English
- Mysticism and its resultsAuthor: John DelafieldLanguage: English
- Mysticism and Logic and Other EssaysAuthor: Bertrand RussellLanguage: English
- Myth and Science: An EssayAuthor: Tito VignoliLanguage: English
- Narrative and Miscellaneous Papers — Volume 2Author: Thomas De QuinceyLanguage: English
- NATURAEAuthor: DomLanguage: English
- Natural Law in the Spiritual WorldAuthor: Henry DrummondLanguage: English
- Nature Cure: Philosophy & Practice Based on the Unity of Disease & CureAuthor: Henry LindlahrLanguage: English
- Nature MysticismAuthor: Mercer, John EdwardLanguage: English
- Never Again! A Protest and a Warning Addressed to the Peoples of EuropeAuthor: Edward CarpenterLanguage: English
- New Thought PastelsAuthor: Ella Wheeler WilcoxLanguage: English
- No and YesAuthor: Mary Baker EddyLanguage: English
- No Compromise with Slavery: An Address Delivered to the Broadway Tabernacle, New YorkAuthor: William Lloyd GarrisonLanguage: English
- No Refuge but in TruthAuthor: Goldwin SmithLanguage: English
- Note Book of an English Opium-EaterAuthor: Thomas De QuinceyLanguage: English
- Notes on the ApocalypseAuthor: David SteeleLanguage: English
- O congresso de Roma: (Conferência realisada pelo delegado portuguez do congresso do livre-pensamento)Author: S. de Magalhães (Sebastião de Magalhães) LimaLanguage: Portuguese
- O doido e a morteAuthor: Teixeira de PascoaisLanguage: Portuguese
- O Vegetarismo e a Moralidade das raçasAuthor: Jaime de Magalhães LimaLanguage: Portuguese
- Occasional Thoughts in Reference to a Vertuous or Christian lifeAuthor: Masham, Damaris, LadyLanguage: English
- OjennusnuoraAuthor: Epictetus, 55-, K. (Kaarle Kustaa) JaakkolaLanguage: Finnish
- Om viljans frihet: Ett föredragAuthor: Frans von SchéeleLanguage: Swedish
- On Being HumanAuthor: Woodrow WilsonLanguage: English
- On CompromiseAuthor: John MorleyLanguage: English
- On Heroes, Hero-Worship, and the Heroic in HistoryAuthor: Thomas CarlyleLanguage: English
- On the Advisableness of Improving Natural KnowledgeAuthor: Thomas Henry HuxleyLanguage: English
- On the Duty of Civil DisobedienceAuthor: Henry David ThoreauLanguage: English
- On the Genesis of SpeciesAuthor: St. George Jackson MivartLanguage: English
- On the Improvement of the UnderstandingAuthor: Benedictus de Spinoza, R. H. M. (Robert Harvey Monro) ElwesLanguage: English
- On the Method of Zadig: Essay #1 from "Science and Hebrew Tradition"Author: Thomas Henry HuxleyLanguage: English
- On the Nature of ThingsAuthor: Lucretius Carus, Titus, 95? BCE-50? BCE, William Ellery LeonardLanguage: English
- On the Prospects of Christianity: Bernard Shaw's Preface to Androcles and the LionAuthor: Bernard ShawLanguage: English
- On the Reception of the 'Origin of Species'Author: Thomas Henry HuxleyLanguage: English
- On the Significance of Science and ArtAuthor: Tolstoy, Leo, graf, Isabel Florence HapgoodLanguage: English
- On the SublimeAuthor: Longinus, active 1st century, Andrew Lang, Havell, H. L. (Herbert Lord), -Language: English
- On WarAuthor: Carl von Clausewitz, Graham, J. J. (James John) [Translator]Language: English
- One Common FaithAuthor: Bahá'í International CommunityLanguage: English
- Opúsculos por Alexandre Herculano - Tomo 04Author: Alexandre HerculanoLanguage: Portuguese
- Opúsculos por Alexandre Herculano - Tomo 08Author: Alexandre HerculanoLanguage: Portuguese
- OrthodoxyAuthor: G. K. (Gilbert Keith) ChestertonLanguage: English
- OrthodoxyAuthor: G. K. (Gilbert Keith) ChestertonLanguage: English
- Our Friend the DogAuthor: Maurice Maeterlinck, Cecil Aldin, Alexander Teixeira de MattosLanguage: English
- Our Unitarian GospelAuthor: Minot J. (Minot Judson) SavageLanguage: English
- Outspoken EssaysAuthor: William Ralph IngeLanguage: English
- Over literatuur: Critisch en didactischAuthor: M. H. Van CampenLanguage: Dutch
- Où va le monde?Author: Walther Rathenau, S. (Samuel) JankélévitchLanguage: French
- Pagan and Christian Creeds: Their Origin and MeaningAuthor: Edward CarpenterLanguage: English
- Pantheism, Its Story and Significance: Religions Ancient and ModernAuthor: J. Allanson (James Allanson) PictonLanguage: English
- Panukala sa Pagkakana nang Repúblika nang PilipinasAuthor: Apolinario MabiniLanguage: Tagalog
- Paradoxes of CatholicismAuthor: Robert Hugh BensonLanguage: English
- Paris TalksAuthor: ʻAbdu'l-BaháLanguage: English
- ParmenidesAuthor: Plato, Benjamin JowettLanguage: English
- Parsifal: Story and Analysis of Wagner's Great OperaAuthor: H. R. (Hugh Reginald) HaweisLanguage: English
- Pascal's PenséesAuthor: Blaise Pascal, T. S. (Thomas Stearns) EliotLanguage: English
- Past and PresentAuthor: Thomas CarlyleLanguage: English
- Percy Bysshe Shelley as a Philosopher and ReformerAuthor: Charles Sotheran, Charles William FredericksonLanguage: English
- Personality in LiteratureAuthor: R. A. (Rolfe Arnold) Scott-JamesLanguage: English
- PhaedoAuthor: Plato, Benjamin JowettLanguage: English
- PhaedrusAuthor: Plato, Benjamin JowettLanguage: English
- Phaethon: Loose Thoughts for Loose ThinkersAuthor: Charles KingsleyLanguage: English