What is wrong with Reductionism?DEACON DOUGLAS MCMANAMAN
Many young people who have good minds for science and math tend to think with a reductionist habit of mind.
Although the reductionist habit of mind makes for good science, it is a flawed method of explaining things ultimately. In other words, it makes for bad philosophy.
Let me begin by making a point about number. Number is multitude, organized and identified and measured by unity. Multitude is plurality, pure and simple, and as such it is unorganized. Think of a continuous extension, like a quantity of milk. To number it, we need a unit, such as a litre. Now, in itself a plurality is unknowable, but it is known only when measured by unity. To reduce a plurality to unity is to number it, and our material world can accordingly be organized into unity. I will return to this.
Consider as well: man has two interiors. The one is physical (i.e., we can look inside his body). But no matter how much we search the physical interior of a man, we will never know what is contained in the other interior (the interior he refers to when he speaks of his "mind" or "heart"). The human being has to manifest it by acting – in this case, speaking. There are also two interiors of any substance, like a carbon atom. The only way to grasp the interior of a carbon atom is to observe how it acts. Its activity reveals its nature. It does not have a conscious interior, like man, but it has a determinate nature. The interior of the atom is not the parts that constitute it. Rather, the interior is the nature of the atom.
But that is just what reductionism denies. Reductionism says that this "thing" is nothing more or other than the parts that make it up. So, there really is no "it". "It" is a word, but "it" is nothing other than parts.
But if I understand "parts", does that not presuppose that I understand "whole"? If I know of the "parts of a thing", does that not presuppose I know "thing"? If I didn't understand "thing", I would not understand "parts of the thing". So, if there is no "thing" or "it", there are no "parts of it". We could not speak of "real parts" if there is no "real whole" or "real thing".
But the reductionist claims that you, as well as anything else, are nothing other than the constituent parts. But what are the parts? The reductionist would say that each part is nothing other than its smaller constituent parts. What is an organ but the cells that make it up? And a cell is nothing other than the parts that make it up, that is, the parts that constitute it.
If the answer is yes, then the cell, or the organ, or the cat or man, is more than the multiplicity of parts that constitute it. The parts are reduced to a unity. That unity is called the cell, or the organ, or the man. That unity renders the multiplicity of parts intelligible. A raw multiplicity is unintelligible unless it is reduced to a unity. That is why we number things. An extension, for example, is measured by a unit called a yard. But a yard is numbered by the unit called a foot, which in turn is numbered or reduced to a unit called an inch. Hence, a foot is 12 inches. A number is a measure of quantity. Without a number, the quantity remains unorganized.
A multiplicity does not give itself unity. The unity comes to it from the outside, from outside the multiplicity. A multiplicity considered in itself is not a unit, and a unit is not a multiplicity. A unit is one. An inch terminates or determines an extension, giving it determination (definition, intelligibility). A litre measures or terminates a quantity of liquid. A pound terminates a quantity of weight, allowing us to determine the weight, to know its weight (i.e., this person is 200 pounds, that milk carton is 2 litres, that table is 5 feet, 6 inches, etc.). At this point the plurality is organized into an intelligible quantity.
One may object and claim that it is not true that "a unit is not a multiplicity. A centimetre is made up of millimetres. Hence, a centimetre is a unit, but it is a multiplicity at the same time."
A centimetre, however, is a unit (one one hundredth of a metre) that measures a meter, but because the centimetre is an extension, it too can be measured. To do so, we have to divide it further. A millimetre is one one thousandth of a meter. And so the unit of measure, like the centimetre, is not outside of the multiplicity spatially. Rather, it is outside of "multiplicity", that is, it is not itself a multiplicity, but a measure of multiplicity. As extended, it is a multiplicity that is open to being measured or numbered. To do so, we need a smaller unit of measure, i.e., the millimetre. But the unit allows us to number multiplicity (quantity, or the multiplicity of parts outside of parts). But "one" itself is not a multiplicity. Multiplicity does not number or measure multiplicity, a unit does.
A single cell, similarly, is an intelligible thing. A scientist sees it as a biological unit, certainly a part of a larger whole (the organ), or a whole unto itself, if it is a single celled bacteria. He begins to analyze it and study its constituent parts.
Now, if the answer to the above question ("Is the cell a determinate part?" "Does it terminate into a definite intelligible part of a larger whole?") is no, then the cell is nothing other than "its" constituent parts, i.e., proteins, amino acids, etc. These in turn are ultimately nothing other than atoms of elements, which in turn are nothing other than subatomic particles, which in turn are nothing but smaller subatomic particles, etc.
The result is that "thing" is not anything in itself. It is always other than "itself". A man is not a thing in itself, a dog is not a thing in itself, a flower is not a thing in itself, a single celled organism, like a bacteria, is not a thing in itself, an atom is not a thing in itself, etc.
Everything is other than "itself". There is no "itself". Nothing has any "interior". Nothing is what it is, but is "other than" what it is.
Nothing has any determinacy. Nothing, therefore, is knowable. Everything is unknowable; for we cannot know what is indeterminate.
But then one has to ask: "How is it possible to understand change?" Take the concept of evolution. When we speak of evolution, we speak of something evolving. But if there are no "things" in themselves, then "nothing" evolves. I can only understand change when I understand that something enduring has changed in some way, i.e., you sat in the sun and became tanned. Your color changes, but you are the subject of the change that endured. "Tanned" is the predicate (John is tanned). But there is no ‘you', no cell, no organism of a determinate species, so what, therefore, evolves? In other words, change can only be understood against the backdrop of that which endures, that which is unchanging. Reductionism is thus incompatible with evolution.
And so, reductionism leads to the conclusion that categorical propositions are impossible. They are not real. For example: "John is a man" or "the cell divides" are nothing more than linguistic constructs that create the illusion of "thing". The principle of identity as well is a construct, and logic, in the end, can be nothing more than a construct.
The reductionist, however, "reasons" to conclusions from given premises. He says things like: The mind is nothing but the brain, and thinking is nothing but firing neurons, or neural biochemistry, and therefore man is not essentially different than brute animals, etc. Some reductionists, not all, proceed further and will conclude from all this that we should stop treating ourselves as privileged creatures, etc. Notice the reasoning from premises to conclusions, even though logical reasoning, which depends on categorical propositions, is impossible if reductionism is true.
Note also their desire that everyone conform to the fundamental truth that "man is nothing more than…" the truth which does not exist in the first place (since all science is a fiction). The truth is that there is no truth, just constructs. And if that is the case, it would seem that all constructs are equally valid and invalid at the same time (in other words, the principle of non-contradiction is also a construct). Which construct, therefore, is going to prevail? It is the one with the most power behind it.
If we wish, however, to hold on to our common sense and avoid this entirely irrational state of affairs, then let us return to the "yes" alternative above. If the single celled organism, for example, is a thing in itself, what is it that reduces the multiplicity to a unity, a determinate thing or entity that can be studied? It is something outside the multiplicity. One cannot appeal to the parts that make it up. The parts are organized into an intelligible whole (unity). The principle of unity is a principle that is outside the parts, a principle that embraces the whole and determines the parts to be what they are. In other words, we must proceed in the complete opposite direction of reductionism. It is the whole that explains the part or parts. Some principle belongs to the whole organism (or atom or bacterium) that determines it (and all its parts) to be what it is. We are back, once again, to the formal cause.
Deacon Douglas McManaman. "What is wrong with Reductionism?" CERC (November 2010).
Printed with permission of Deacon Douglas McManaman.
Copyright © 2010 Douglas McManaman
Not all articles published on CERC are the objects of official Church teaching, but these are supplied to provide supplementary information.