Providing a theory of consciousness has been one of the most important issues in philosophy of mind. Tim is pretty much a skeptic that this is a valid (neuro)scientific endeavor. His stance arises because consciousness itself is a pretty un-quantifiable concept. There isn’t a device or test that can measure the “degree of consciousness” and often it gets conflated with concepts like being awake, intention, or attention. Derek is open to the possibility of a “science of consciousness,” but he is currently unimpressed by what’s been offered so far. His position agrees with Tim that most of the definitions of consciousness are vague and unhelpful; they usually define consciousness in terms of what it’s not. However, scientists can sometimes make new discoveries about phenomena of which we have vague or incomplete concepts.