These files contain Sellars's unpublished manuscript drafts, which were the earlier versions of his published works. These manuscripts are arranged alphabetically by manuscript title. In a few instances, the manuscript drafts are augmented by related correspondence. The vast majority of the revisions and inserts added to the manuscripts were done by Sellars. However, there are a few manuscripts that contain editor notations. In general, the revisions range in content from grammatical changes to extensive modifications of Sellars's philosophical arguments. These revisions reveal Sellars's tendency to cross out entire sections of his argument and insert new pages. The bulk of these files are either typed or mimeographed. A small portion of the files are entirely handwritten and can be rather difficult to decipher. The files vary in length. Some of the files provide only one draft of a particular manuscript, while a larger portion of the files actually contain multiple drafts of the manuscript and document various points in the editorial process. Whenever possible, these multiple drafts are arranged chronologically from the earliest to the most developed version. All of the manuscripts are philosophical in nature and focus on Sellars's interests in the areas of epistemology, philosophy of language, philosophy of mind, and ontology.