I first came across the work of Joseph Kosuth in Wellington, New Zealand, where, in 2000, he did an installation for the University Art Gallery called Guests and Foreigners, Rules and Meanings.   I have ever since admired the way he combines history, lettering, allusion and meaning in complex museum settings.   The granddaddy of conceptualism, he started using neon lights in 1965, before Bruce Nauman, Tracey Emin and the rest.   He’s got an exhibition opening tonight at Sprüth Magers in Grafton Street.