Examples from literature

• Dullards, unless their brains are stunted, may develop surprising intellectual keenness. 
• I am taking him not to be a dullard but a poet. 
• In tracing the natural history of a public-house I have found the respectable dullards the most revolting of my subjects. 
• No man but a dullard without a spark of imagination could have witnessed the scene presented at that moment without experiencing a thrill which he would have found it difficult to describe. 
• Only dullards, or the unthinking, can be surprised by the ease with which a quick-witted man, having some knowledge of Latin, can learn to read a novel in French, Italian, or Spanish.