The author says, “Reductionism fails when we try to use it in the opposite direction.” I do not completely agree with this statement. From what I understand, reductionism is breaking down a complex system into smaller parts, until it cannot be broken down further, and studying the system at this core level. This gives us a lot of information on how the individual elements of a system work, but this is not the final step. The ultimate goal is to understand the system itself. That can only happen if, after reductionism, we let ourselves use the knowledge of these individual simpler units to build back up the full system and study it as a whole – how are these individual agents interacting with each other and what does that tell us about the system? This is a bottom-up approach, i.e., understanding reductionism in reverse.
In fact, the author himself touches upon this and contradicts himself when he quotes Bertand Russel in the beginning, “The point of philosophy is to start with something so simple as to not seem worth stating, and to end with something so paradoxical that no one will believe it.” This is nothing but reverse reductionism. This is what we often do in math too. We start with an obvious (trivial) statement that no one will seem to contradict, and then build something upward from there, leading to a complex proof or a result that may be counterintuitive or ‘mind-boggling’ as the mathematicians say. Since most of the sciences depend on math, they follow a similar pattern of experimentalism and theorization. And what does science aim to do? Science studies and tries to explain the daily observations and occurrences in nature. So, doesn’t this tell us something about nature as well? Yes, it does. And it is that nature itself governs by the law of reverse reductionism. Nature defines how the individual elements behave and then puts them together, letting them run free reign – agents interacting as they wish – and thus creating complex systems.
Hence, if we wish to understand the complex systems in nature, we must employ the strategy of reverse reductionism after reductionism. Understanding reductionism in the reverse direction does not fail us, but rather it is an essential next step.