The most common criticism of Gardner's MI theory is "the belief by scholars that each of the seven multiple intelligences is in fact a cognitive style rather than a stand-alone construct". Others consider the theory not to be sufficiently empirical. This perspective has also been criticized on the grounds that it is "ad hoc": that Gardner is not expanding the definition of the word "intelligence", but rather denies the existence of intelligence as traditionally understood, and instead uses the word "intelligence" where other people have traditionally used words like "ability" and "aptitude".