The series comprises a commonplace book, 1734, containing notes on Greek and Latin literature, ancient history, philosophy and science, other extracts and educational notes on similar subjects, 1820, 1841, 1925, and book lists, 1819-1830.

A holograph essay entitled 'Traethawd Beirniadol ar Athroniaeth William James' by 'Diwyd o Geredigion' [the Reverend William Benjamin, Garth, Llangollen]. The essay was awarded the prize at the National Eisteddfod at Aberystwyth, 1916.

Autograph drafts of two essays by John Cowper Powys entitled 'Scepticism' and 'Elementalism or My Philosophy', the latter heavily revised.

An interleaved copy of a printed syllabus of lectures on experimental philosophy given by Dr. Hornsby, with notes, 1793-1795, by Walter Davies.

The first and main accrual, made in 1977, comprising some twenty-one boxes and described elsewhere, reflects J. R. Jones' valuable contribution to nationalist and religious philosophy, and his wider contribution to the field of philosophy and his specific interest in the nature of the self. -- The first deposit is mainly in Welsh and the catalogue prepared at NLW is also in Welsh. It consists mainly of his publications, books, pamphlets and articles, together with his academic notes. The correspondence is scarce, no more than forty individual letters, but there is an extensive collection of newspaper cuttings containing annotations in his hand. -- The second group, described here, consists mainly of notes dating from his period as a student and as a lecturer. However, it does also include a small collection of offprints and other printed material, together with some personal possesions once belonging to Professor A. E. Heath. -- Despite the fact that the notebooks have been arranged into two series, notes taken as a student and notes used to deliver lectures, there is some evidence to suggest that the earlier notes were used at a later date to prepare lectures. Some notebooks belonging to the same series are split between the two accruals - attention has been drawn to this whenever possible.

Letters from John Cowper Powys to his brother, Llewelyn Powys, [1923], his companion, Phyllis Playter, [?1924], 'George', 1958, and a 'Mr London', [?1940s], the latter dictated by Powys to Phyllis Playter; together with miscellaneous literary papers, which comprise drafts of poems, [c. 1900]-1953, including an early version of 'Samphire' (published in Horned Poppies ... (1986)) and of several unpublished anniversary poems addressed to Phyllis Playter; a draft, [?1900]-1902, of an unpublished preface to poems by Alfred de Kantzow; an ink and pencil sketch of the map which forms the end-papers of Powys's novel Ducdame (1925); and drafts of the opening of a philosophical work, 1938, and of a speech in Welsh, [1935x1954], the latter composed by Powys while he was living in Corwen.

Notes of lectures on the philosophy of the mind taken by Owen Jones when he was a student at University College, London, 1861.

An arithmetic and writing book of a Miss Evans, 1827, afterwards used by Aaron Francis for draft articles ('Yr Annibynwyr a'u credo', 'The Christian Alliance and its creed', 'Sefydliadau gwladol o grefydd yn dinystrio seiliau cyfrifoldeb dyn', 'Mental Philosophy') and poetry ('Prydnawn yn Chwefror: aralleiriad o Longfellow', 'Yr Aderyn a'r Llong', 'The Consumptive', 'A deathbed scene during a storm', 1852, 'Benjamin bach ar goll', 'Pellebyr môr y Werydd', 'The Missionary', 'The Mochnant Waterfall', 'Hoffder Cymro am ei wlad', 'Pa le maent', 'Y Cynhaeaf', 'Marwolaeth fy chwaer', 'Death of the Darling boy', 'Williams o'r Wern', 'John Elias' and 'Anghariad').

A notebook containing notes on forms of church government, philosophy, the early history of Capel-y-ffin Baptist Church, border antiquities (Ewyas Harold, Kilpeck, Kenderchurch, Rowlstone, Michael Church, Patricio, Craswall, etc.), characteristics of early architecture, the 'arrangement' of Llanthony Abbey, etc., together with some statistics of a Bible class at Pandy, 1873.

Notes on the doctrine and the rite of baptism and on philosophy; a paper on Sir John Oldcastle, styled Lord Cobham (d. 1417), read to the Cambrian Archaeological Association at Abergavenny, [18] August 1876; notes from Edmund Jones: ... Account of the Parish of Aberystruth (Trevecca, 1779); notes of visits to Gloucestershire and to Bala, 1882-1883; etc.

Miscellaneous notes and extracts relating to church history, theology, philosophy, etc.

Notes of lectures on algebra, natural philosophy, mechanics, philosophy, etc., taken at the Independent College, Brecon, 1845-1847, by Thomas Davies, Tre-lech.

An incomplete notebook of Samuel Jones (1628-97), nonconformist minister and teacher, of Brynllywarch, Glamorgan, containing notes of sermons; a catalogue of his books; accounts, 1664-5 and undated, including particulars of receipts and disbursements for 'Sister Prichard' at Brymbo, etc., and of payments at Whitechurch, Newport, Norton, Meredin, Dunchurch, Holmby, Horton, Hockley, Harding, Hilmorton, etc.; and extracts from a philosophical work (e.g. 'De accidente', 'De proprietatibus praedicabiliorum', etc.).

Notes on Greek grammar, philosophy, the gospels, etc. written by Morris when a pupil at Sherborne School, 1851.

Notes on Greek grammar, philosophy, etc., 1845-1852.

An anthology compiled by Basil Roberts-Jones ('Rhys ap Iorwerth'), Cardiff.

A collection of autograph manuscripts of philosophical works by the Reverend W. Tudor Jones, Unitarian minister and philosopher.

Four notebooks and a series of disbound notebooks and loose leaves, [c. 1900]-[c. 1902], containing parts of a projected first novel by John Cowper Powys comprising substantial drafts of a romance set on the Sussex Downs; together with numerous, shorter fragments of narrative, mainly passages of prolix theological and philosophical discussion, and Rabelaisian fantasy, involving characters based on the author's friends. Also included are heavily worked drafts of unpublished poems (NLW MS 23672E, ff. 57-60 and ff. 135-137 verso, 138 verso, 139 verso-140, inverted text; NLW MS 23673E, ff. 146 recto-verso, 147 verso, 154 recto-verso, 155 verso, 156 verso-60 verso, 161 verso-162, inverted text; NLW MS 23676E, ii, ff. 250 verso-251, 253 verso-255, 259 verso, 260 verso, 261-262 verso, 263 verso, 264 verso-265 verso, 266 verso, 267 verso-268 verso, 269 verso, 270 verso, inverted text); and notes on Shakespeare's The Tempest, Macbeth, Richard III and The Taming of the Shrew (NLW MS 23673E, ff. 148-153 verso, inverted text), possibly for use in Powys's lecturing work.