"What I argued for then (Searle 1984b) and repeat here is that one can accept the obvious facts of physics - that the world consists entirely of physical particles in fields of force - without denying that among the physical features of the world are biological phenomena such as inner qualitative states of consciousness and intrinsic intentionality."
Later in Ch. 10 he writes this:
"I see the human brain as an organ like any other, as a biological system. Its special feature, as far as the mind is concerned, the feature in which it differs remarkably from other biological organs, is its capacity to produce and sustain all of the enormous variety of consciousness life."
In the Epilogue to Mind, A Brief Introduction, he writes this:
"I have tried to give an account of the mind that will situate mental phenomena as part of the natural world. Our account of the mind in all of its aspects - consciousness, intentionality, free will, mental causation, perception, intentional action, etc. - is naturalistic in this sense: first, it treats mental phenomena as just a part of nature. We should think of consciousness and intentionality as just as much a part of the natural world as photosynthesis or digestion. Second, the explanatory apparatus that we use to give a causal account of mental phenomena is an apparatus that we need to account for nature generally. The level at which we attempt to account for mental phenomena is biological rather than, say, at the level of subatomic physics. The reason for this is that consciousness and other mental phenomena are biological phenomena; they are created by biological processes and are specific to certain biological organisms."
He then goes on to tell us that "science does not name an ontological domain; it names rather a set of methods for finding out about anything at all that admits of systematic investigation." So the "explanatory apparatus" that we use to account for nature generally, and that we must use to investigate the mind, is that of ordinary empirical science. Searle's distinctive approach to the philosophy of mind is to hold these two principles in tension: 1) That the traditional philosophical features of the mind - e.g. consciousness, free will, intentionality - are real things in the world that require explanation rather than merely being explained away, and 2) The empirical sciences are the only way to systematically explore nature, and so the empirical sciences (specifically, biology) must account for the phenomena referred to in principle #1.
The problem for Searle's philosophy is that the tension of his two principles is fatal. There is consciousness, free will and intentionality in science, but it is all found in the mind of the scientist conducting the science, not in any of the products that result from his science - even if that product is a scientific account of the mind itself. Neuroscientists, for example, spend a lot of time stimulating the brains of subjects in various ways, inducing sensory experiences (seeing colors, hearing sounds), making them feel different things from sadness to religious-like awe, or changing their perception of themselves or the world. These experiences are mapped back onto the brain regions from which they are stimulated. There is no possible freedom on the part of the subjects; they either see the color or they don't. Suppose scientists tried to stimulate a "free act." They stimulate an area of your brain and you raise your right arm. They stimulate the same area again and you raise your left arm. They stimulate it again and you whistle "Dixie." They stimulate it yet again and you recite the Nicene Creed. What would the scientific conclusion be? That they had stimulated a "free act?" No, the only possible scientific conclusion would be that their experiments had not been done with sufficient care and that they were not really stimulating exactly the same brain cells every time. In fact, your physical brain will not be in exactly the same condition from each experiment to the next, since it is continually changing in minor material ways as a matter of nature. The only possible scientific result is "failed experiment", not "science discovers free will", for the latter is an impossibility.
Similar points can be made with respect to the other interesting features of the mind. The essential feature of consciousness, for example, is that it is a viewpoint from the center of the world, the "subjective viewpoint." The subjective viewpoint in science is that of the scientist. The subjective viewpoint of the subject is necessarily treated as an objective element in the scientific world of the scientist, with the scientist and not the subject at the center; the subjective viewpoint of the subject therefore appears in the scientific world as something it is not, or rather, it doesn't appear at all. There is consciousness in science, of course - the consciousness of the scientist and no other.
Daniel Dennett is a philosopher who accepts the same principles as Searle, but also accepts the obvious and necessary results. If science is how we know reality, and the subjective features of the mind do not appear for science, then we must conclude that the subjective features of the mind are not real. Searle sums up Dennett's position smartly in Ch. 5 of his Mystery of Consciousness:
"The problem of consciousness in both philosophy and the natural sciences is to explain these subjective feelings. Not all of them are bodily sensations like pain. The stream of conscious thought is not a bodily sensation comparable to feeling pinched and neither are visual experiences; yet both have the quality of ontological subjectivity that I have been talking about. The subjective feelings are the data that a theory of consciousness has to explain... The peculiarity of Daniel Dennett's book can now be stated: he denies the existence of the data. He thinks there are no such things as the second sort of entity, the feeling of pain. He thinks there are not such things as qualia, subjective experiences, first-person phenomena, or any of the rest of it. Dennett agrees that it seems to us that there are such things as qualia, but this is a matter of mistaken judgment we are making about what really happens."
Dennett is exactly right to deny the existence of the data, for the data as Searle describes them are not scientific data. "Subjective experiences" cannot be scientific data, for the only subjective experience that counts in science is the subjective experience of the scientist; the subjective experience of the subject appears in science only as an objective element in the subjective experience of the scientist; in other words, not as a subjective experience at all. Since, for both Dennett and Searle, science determines the nature and extent of the real, subjective experiences can't be real. Searle's two basic principles are in fundamental conflict.