Science makes use of sensory verification when dealing with the details of reality. As useful as this approach is, this approach does not allow science to fully address all phenomena in nature.
For example, say I had a dream and I decided to relate the details of my dream. We have all had dreams to know that dreams can and do occur. However, there is no way to verify the details of any given dream, from the outside, using sensory verification.
Even if I was completely honest and accurate these details cannot be proven by the scientific method, nor could anyone reproduce my dream in the lab. Even if I was telling the truth, the truth will need to be denied as not verifiable by science. One would need to have faith that I am an honest investigator relating data to my colleagues. This is an example of a type of phenomena that is real, but is only subject to individual verification, but not group verification via science. Science has to deny it based on its philosophy.
Dreams are the tip of the iceberg, in terms of a wide range mind phenomena that are not fully verifiable using the scientific method. The areas of science that deal with these things are called soft science, since it does require a degree of faith and empathy beyond sensory verification. The Psychologist has to have faith in the patient telling then the truth, with the doctor looking for cues to verify the truth, so they can collect needed data.
When the philosophy of science was developed, the founding fathers consciously made the choice to factor out all affects that were not verifiable by the senses. They limited science to direct sensory verification. For example, If we all were in the woods at night and heard a noise, and each person interprets the sound in a different way, science will only deal with what we all hear; noise. The rest is not addressed unless added sensory evidence is supplied.
Even though consciousness is the most important tool of science, there is no consensus definition for consciousness by science. The reason is although we can individually observe the phenomena of consciousness from the inside of our minds, others cannot verify another person's first hand data with external sensory input. There is no way to form a consensus definition using the scientific method.
The problem this creates for science, is the main tool of science is human consciousness. If we cannot define it using science, then how do we know if this main tool of science is properly calibrated? There could be bias, that we assume is the zero point, without being able to verify using science.