Meaning of pons asinorum in English:

pons asinorum

Pronunciation /ˌpɒnz ˌasɪˈnɔːrəm/


  • The point at which many learners fail, especially a theory or formula that is difficult to grasp.

    ‘After he had mastered the fifth proposition as easily as its predecessors, Frank told him that people generally found it difficult - it is the famous pons asinorum which puts a stop to many a budding geometrical career.’
    • ‘It is the pons asinorum of the relationship between economics and politics.’
    • ‘We used to read the first book of Euclid as far as pons asinorum; but regularly as we reached the dreadful pass we were turned back for a revisal.’


Mid 17th century (as a term in logic, denoting a diagram or method for finding the middle term of a syllogism in Aristotle): medieval Latin, literally ‘bridge of asses’. The expression is used to denote the fifth proposition of the first book of Euclid, as it was considered the first real difficulty encountered by a reader in this work, but this use is later than the sense ‘an obstacle or problem that will defeat an unskilled or foolish person’ in English, Latin, and French. It has been suggested that asses were unwilling to go on to hump-backed bridges because they could not see beyond the summit as they began to cross.