The collection contains correspondence; lecture notes on history; newspaper cuttings; papers of other members of the family, including an undated letter of Danton which belonged to A H Beesly; printed reports; pamphlets containing articles by or about Beesly; other pamphlets and reviews; other printed works; and an autographed photograph of Karl Marx. The correspondence is rather slight and only isolated letters from individual correspondents are preserved. There are sets of Beesly's own letters to Henry Crompton and to Frederic Harrison which were probably returned to the family after his death. There are also a few letters to Beesly's brother A H Beesly and to Alfred Beesly, E S Beesly's son.

Correspondence to and from Frederic and Ethelberta Harrison, including family correspondence and photocopies of Harrison's correspondence with Edward Spencer Beesly; Frederic Harrison's writings and speeches, including diaries on subjects such as the cotton famine in Lancashire, essays on subjects such as positivism, peoples education and the French Revolution, autobiographical notes, and ephemera; and press cuttings.

Minute books, account books and annual reports; correspondence (mainly of Henry Tompkins and Donald Fincham as Secretary), with members, with other Positivists, Humanists and Historians, and concerning the August Comte Memorial Trust; notes and papers by Henry Tompkins, including a short autobiography, addresses on positivist subjects, and notes on books he had read; other positivist writings, including pamphlets, reports and the text of talks; and various ephemera and pictures, including photographs of members, broadsheets and programmes, typescripts of correspondence between August Comte and George Lewes, and notes on the history of the Society.