The factor of the unknown should be accounted for in your thought process. Here are three questions to ponder:
Question 1: Can you be certain that there is information which you do not possess?
Keep in mind, if you don’t know the answer to this question, you just discovered it.
Question 2: If there is information which you know you do not possess, to what degree of certainty can you conclude anything?
This question has deep consequences, especially for the hard sciences. I try to answer it here.
Question 3: Is it possible to accurately categorize any part of the unknown?
In other words, when discussing brain function, can we work with the category of unknown physical “neural processes”? If so, that means we actually can know certain properties of the unknown (which makes them less unknown). This makes “unknown” knowledge more like “non-specified” knowledge with which we can work.
For example, we don’t really know what dark matter is yet, but can we know it is a physical process which should play by some laws of physics, even if those specific laws have not been “specified” (“discovered”) yet? Can we be certain about the unknown having properties, or is it just a best guess?