The manuscripts included in this volume are held in the Special Collections Centre in the Sir Duncan Rice Library, University of Aberdeen. The majority of the manuscripts transcribed here are found in the Birkwood Collection, MSS 2131/1–8, while the remainder are from the deposit of Reid's papers catalogued as MSS 3061/1–26. All of the manuscripts in these two collections have been digitised and are available through the Special Collections Centre website (https://www.abdn.ac.uk/historic/Thomas_Reid/index.shtml). The history of these manuscripts, as well as others housed in the Special Collections Centre, will be discussed in an appendix to volume 10 of the Edinburgh Edition of Thomas Reid.

Prior to Reid's death on 7 October 1796 he appears to have sorted at least some of his papers into thematic groups, for among the Birkwood Collection wrappers survive in his hand headed ‘Politicks’ and ‘Nat Hist’ (i.e. ‘Natural History’). Immediately after he died, his papers were organised into bundles by his close colleague, the Glasgow Professor of Logic and Rhetoric George Jardine, who a few months later collaborated with his fellow professors Patrick Wilson and Archibald Arthur in choosing the titles from Reid's personal library that were gifted to the University in early 1797 by Reid's daughter Martha. Of the eleven known bundles assembled by Jardine, three consisted of manuscripts on mathematics and the natural sciences, including one made up exclusively of notes from the lectures on natural history and natural philosophy Reid gave as a regent at King's College, Aberdeen, in the period 1751 to 1764. A fourth bundle, which included papers Reid had read to the Glasgow Literary Society, contained material on mathematical and scientific subjects which eventually resurfaced in the public domain as part of the MS 3061 deposit. Apart from this particular bundle, the contents of the other ten bundles have, over time, lost their original arrangement. The Birkwood Collection as we now know it was given shape initially by A. T. W. Liddell in the 1950s, whose ordering of the surviving Reid manuscripts in the Collection was revised by David Fate Norton in the 1970s.