Professor Lee M.Pierson and Monroe Trout have written an important article on “What is consciousness for?” in New Ideas in Psychology (Volume 47, December 2017, Pages 62-71). From the introduction:
Perhaps the greatest challenge faced by science today is to understand, in scientific terms, the nature of consciousness: what causes it (the “hard problem,” so named by the philosopher David Chalmers) and what it causes (the “harder problem,” so named by the cognitive scientist Stephen Harnad). We cannot at present solve the “hard problem” of how natural selection was able to produce consciousness, that is, answer the question of how consciousness emerged in the evolution of some animals. We can, however, go a considerable way toward solving the “harder problem” of why consciousness evolved, but, we believe, only through consideration of the adaptive value of volition (also known as “free will”: non-deterministic, non-random choice).
So, our primary hypothesis is: The ultimate adaptive function of consciousness is to make volitional movement possible. Consciousness evolved as a platform for volitional attention; volitional attention, in turn, makes volitional movement possible. Volitional movement (including any automatized components) is the sole causal payoff, the “cash value” of volitional attention and thus of all conscious processes. There is no adaptive1 benefit to being conscious unless it leads to volitional movement. With volition, the organism is better able to direct its attention, and ultimately its movements, to whatever is most important for its survival and reproduction. (Neural processes alone, as we shall see, cannot perform this function as effectively as can neural processes combined with consciousness.) Without the adaptive benefits of volitional movement, consciousness would probably never have evolved.
Since the ultimate2 adaptive purpose of consciousness is to manage volitional motor movement,3 consciousness is properly classified as part of an animal’s motor control system. (Plants do not need consciousness because they are “planted.”) There appear to be two fundamental types of animal movement: automatic and volitional. Although volitional and automatic movements are both implemented by non-conscious neural processes, volitional movements, unlike automatic movements, are initiated consciously. To elaborate on the meaning of our primary hypothesis: 1) Volitional action4 (i.e., non-deterministic, non-algorithmic, non-automatic, non-random action that is freely-willed in the “libertarian” sense) exists. 2) All conscious organisms, if unimpaired, are capable of some kind of volitional action. 3) Volitional action does not merely require consciousness; it is the raison d’être of consciousness. 4) Conscious organisms can volitionally override some of their neural processes. 5) Non-volitional movements do not require conscious involvement. 6) Consciousness is the top manager of the brain; it does not work on the neural assembly line.
We believe that ours is the only hypothesis about the function of consciousness that adequately answers what we call the “Key Question”: “Is consciousness itself causally involved in this function, or is this function performed entirely by neural processes?” For example, the hypothesis that the function of consciousness is “detection” would not adequately answer the Key Question, because there is no evidence that anything other than a neural process is implicated in the actual performance (as opposed to any possible volitional initiating or sustaining of the performance) of detection (cf. Velmans, 1991a).
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