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The Gestalt psychologist Kurt Koffka made a famous statement: the whole is other than the sum of its parts. The statement is often translated to English as, "The whole is greater than the sum of the parts."

Koffka did not like that translation. He firmly corrected students who substituted "greater" for "other" (Heider, 1977).

"This is not a principle of addition," he said. Koffka's point was that larger scale systems (wholes) have characteristics not present in their smaller parts.

[For more about how that relates to Gestalt psychology, see this page in my online introductory psychology textbook.]

Properties of the whole, not found in isolated parts, are called emergent properties. The concept of emergence is commonly offered as an antidote to reductionism.

Reductionism, in turn, is commonly treated as a bogeyman, a bad aspect of modern science. Reductionism, at its worst, is signaled by the phrase "nothing but." An example of a reductionist approach to the mind would be: "Don't bother talking about the mind or consciousness, it is nothing but neurons."

No scientist really thinks that way. Reduc­tionism is therefore a straw man. It is a position that is set up, rhetorically, in order to be knocked down.

A critic will call a position reductionist when (in the opinion of the critic) there is too much emphasis on small parts and not enough emphasis on larger organizational patterns. When reviewing textbooks on Health Psychology a few years back, I noticed almost all started out by saying they adopted a holistic approach, in contrast to the reductionist position of (unspecified) medical professionals.

I suppose they meant they take human expectations and feelings of well being into account, instead of treating people like a mass of body tissues. But the truth is that no medical professionals treat people that way, unless they are very odd.

In reality, few scientists defend reduction­ism. One who does is physicist Steven Weinberg.

Weinberg argues for reductionism in principle, saying that quantum mech­anics should be able to explain every­thing. However, as chemist Ashutosh Jogalekar pointed out:

[Weinberg's] extolling of reduction­ism as being able to ultimately account for all kinds of phenomena is a trivial statement; it's like saying that everything is made out of atoms. So what? That hardly helps us cure cancer. (Jogalekar, 2011)

No scientist is a practicing reductionist in the sense of thinking only smaller compo­nents of a system matter for explaining a system. As Sean Carroll put it:

You could object to the claim that "the best way to understand complex systems is to analyze their compo­nent parts, ignoring higher-level structures" but only if you can find someone who actually makes that claim. (Carroll, 2010)

What is the argument against reduction­ism? Reductionism leaves out organ­ization. An automobile is not merely a collection of parts.

One could put car parts in a room and say, "This room contains nothing but car parts" but the room would not contain a car. Organization matters.

When components are put together into an organized system, the system may exhibit properties not found in the components by themselves. That is called emergence.

A classic example is water: H2O. Water is liquid at room temperature, and that is one of its most important properties.

Hydrogen and oxygen, the components of water, are both gasses at room temperature. Few people would predict that combining two gasses would produce a liquid. Liquidity is an emergent property.

The example of hydrogen and oxygen combining to form water is a classic example of emergence. So it has become trite.

When asked about emergent properties of systems, skeptic Michael Shermer (in Dobson, 2014) could not resist giving an unexpected answer: "Yes, I would predict the properties of water. I would point to the atomic bonds between H and O and how they make it slippery when liquid, but a great solvent, then solid when frozen..."

However, this is post-diction, not prediction. Shermer knows the properties of water from life experience and studying chemistry. To most people, the properties of water are not at all predictable from the properties of hydrogen gas and oxygen gas.

Perhaps Shermer was making a slightly different point: surprise or unpredict­ability alone should not be what defines emergence. What defines emergence is the presence of a property in a system that is not present in the components alone.

Liquidity at room temperature is present in water, but it is not present in hydrogen or oxygen alone. Therefore, whether it surprises you or not, and whether you can explain it with physics or not, liquid­ity at room temperature is an emergent property of water.

Consciousness is often described as an emergent property of brains evolving on earth. This is true, but it tells us nothing about what consciousness is or how it evolved.

Indeed, anything that develops or evolves was emergent at some point. It previously did not exist, and then it appeared. To find out how it emerged, one must analyze the organization of the system and its history of development.


Carroll, S (2010, Nov 3) Physicalist Anti-Reductionism. Retrieved from:

Dobson, A. (2014) Mathematical models for emerging disease. Science, 346, 1294-1295.

Heider, G.M. (1977). More about Hull and Koffka. American Psychologist, 32, 383.

Jogalekar, A (2011, April 19) Dirac, Bernstein, Weinberg and the limits of reductionism. Retrieved from:

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