it is well known that charles l. Dodgson (alias lewis carroll, 1832-1898) worked on a logic treatise that would popularise the subject of symbolic logic. The first part appeared in 1896 but the next parts never appeared. It has been claimed that carroll worked in isolation and did not read the main works of his time. the object of this paper is to inquire what carroll's private library teaches us on his readings. the content of this library is known thanks to the sale catalogues that were issued when the library was auctioned at carroll's death. this paper provides an overview of the logic books owned by carroll. then, it investigates the extent to which carroll was acquainted with the main logic works of his time. Finally, the paper considers some methodological issues related to the use of 'library arguments' in intellectual history.