This profound question is raised by French GM Vladislav Tkachiev, who wonders if Vassily (aka Vasil) Ivanchuk is a genius.  His colleagues are split on the issue, while he himself does not offer an opinion. I'm not sure the word has any clear sense, so while we can obviously say that Ivanchuk is a brilliant and immensely creative player declaring him a genius may be more a matter of taste and emotion than anything objective. But have at it, and if you want to weigh in with some useful remarks on the nature (if any) of genius, feel free.