‘The question of synaesthesia’ looks at arguments against the Neonatal Synaesthesia Hypothesis and at other controversies and outstanding issues facing the field. It discusses the consistency-over-time feature and explains that although synaesthetes are highly consistent, they are not necessarily 100% consistent, and some synaesthetes might not be consistent at all. Is synaesthesia truly consistent over time as a definitional criterion, or does consistency over time merely characterize a subset of synaesthetes? There is also an imbalance between understanding the synaesthetes in English-speaking cultures and understanding synaesthetes worldwide, as well as between different types of synaesthesias. Despite the huge recent advances in understanding synaesthesia and how it affects synaesthetes, there is still more to learn.