ABSTRACT: Global climate change (GCC) is the most widespread environmental peril facing tropical coral reefs, yet the capacity of scleractinian corals to survive the challenge is not well understood. Acclimatization is a primary mechanism by which organisms match their physiology in a timely and beneficial way to a rapidly changing environment, and so it is not surprising that the question ‘can corals acclimatize to GCC effects?’ is a central theme in coral reef science today. Here, we argue that acclimatization in corals, as in all organisms, is axiomatic—i.e. evident without proof or argument—and that the emphasis on whether corals can acclimatize to GCC is distracting. The key to understanding how corals will respond to future environmental challenges lies in understanding the extent to which acclimatization is important. This is a subject that has received great attention in other systems, and we think that coral biologists can benefit from a deeper understanding of the classical physiological expression of acclimatization, and a broader appreciation of the experimental designs that are required for elucidating the complex relationships among physiology, physical conditions, and recent history.