Official language to the government in their native languages. In countries that do not formally designate an official language, a "de facto" national language usually evolves. English is the most common official language, with recognized status in 51 countries. Arabic, French, and Spanish are also widely recognized. An official language that is also an indigenous language is called "endoglossic", one that is not indigenous is "exoglossic". An instance is Nigeria which has three endoglossic official languages. By this the country aims to protect the indigenous languages although at the same time recognising the English language as its lingua franca. Around 500 BC,
What Is Art? to justify their own tastes. Jahn notes the "often confusing use of categorisation" and the lack of definition of the key concept of emotion. Bayley writes that "the effectiveness of "What is Art?" lies not so much in its positive assertions as in its rejection of much that was taken for granted in the aesthetic theories of the time". Noyes criticises Tolstoy's dismissal of beauty, but states that, "despite its shortcomings", "What is Art?" "may be pronounced the most stimulating critical work of our time". Simmons mentions the "occasional brilliant passages" along with the "repetition, awkward language, and loose terminology".