At the other end of the spectrum, Eco has been praised for his levity and encyclopedic knowledge, which allowed him to make abstruse academic subjects accessible and engaging. In a 1980 review of "The Name of the Rose", literary critic and scholar Frank Kermode refers to "Theory of Semiotics", as "a vigorous but difficult treatise", finding Eco's novel, "a wonderfully interesting book – a very odd thing to be born of a passion for the Middle Ages and for semiotics, and a very modern pleasure." Gilles Deleuze cites Eco's 1962 book "The Open Work" approvingly in his seminal 1968 text "Difference and Repetition", a book which poststructuralist philosopher Jacques Derrida is said to have also taken inspiration from. In an obituary by the philosopher and literary critic Carlin Romano, meanwhile, Eco is described as having ", over time, the critical conscience at the center of Italian humanistic culture, uniting smaller worlds like no one before him."