neuroscience disappears when the complex whole is decomposed

The apparent thinking behind deflationary claims like “X is nothing but” is that partial truths can fully explain larger, more complete and essential truths. But in most cases the essential truth concerns the whole, and wholes cannot be explained simply by decomposing them into their constituent parts. There is some reality and autonomy to each level of inquiry in any given scientific investigation or field. To state the obvious: water has something that hydrogen and oxygen molecules do not have when considered separately. A behavior, a cultural norm, a mental experience, and a cognitive process all have something that cannot be found when each phenomenon is decomposed into its constituent parts. The whole, particularly in the realm of behavior, is always greater than the sum of its parts.
​
Thus, the reductionist program of attempting to understand phenomena via decomposition of the whole into parts must always remain radically incomplete, even though it is a valuable and necessary program. To really grasp the nature of an object or process you do, indeed, need to understand its parts, but you also need to understand what emerges when those parts are put together and interact over time in the right way. If parts were all that mattered then we could ignore the wholes that emerge from their interactions; but doing so would in fact lead us to miss hugely important aspects of reality. For “emergent” wholes typically possess unique causal properties themselves that are not reducible to the powers of their constituent parts and cannot, even in principle, be predicted from those parts. Music, for example, can do things in the world that auditory cortical firings by themselves cannot. 

Stimulation of cortical auditory neurons may (under certain contextual conditions) trigger a musical experience; but that experience may in turn trigger downstream effects (e.g. the desire to weep or to jump for joy) that have nothing to do with and have never been correlated with auditory cortical firing patterns. Moreover, if we choose to ignore emergent entities, we will miss all the things in the universe that are novel or just coming into being, which is not how one does real science. Therefore, the “nothing but” reductionist program is inherently incomplete. It necessarily ignores unique causal properties of emergent wholes and it does not “see” anything really new in the universe.

Here.