The antonyms for the word "immutableness" are many and varied. These include terms such as changeability, variability, unpredictability, inconsistency, and flexibility. While immutableness suggests an unwavering state of being, these antonyms refer to a state of flux or the ability to adapt to new conditions. For example, a person who is changeable may be able to adapt to new situations more quickly than someone who is immutable. Similarly, a system that is flexible may be more responsive to changes than a rigid, immutable system. In short, while immutableness has its virtues, the ability to change and adapt is often equally important.