Reductionism: Keeping It Minimal


As a first blog entry I want to introduce and explain the concept of reductionism as it features in the philosophy of science for the purpose of questioning the familiar physicalistic reductionist stance. Readers should become familiar with the idea of reductionism (or reductivism), its motivation, importance, and learn an alternative attitude toward it.

From the latin, we’re told that to reduce is roughly (and firstly) to bring back. If I reduce a lego castle I bring it back to the more basic stuff out of which the castle was made − it’s individual lego pieces. This, to my mind, is the best place to begin to see how the concept of reduction is used in the philosophy of science. A reductionist maintains that of two apparently disassociated entities, properties, phenomena, events, laws, principles, or whatever else, one can be brought back to the other; or less formally, one can be explained, derived, said, characterized, or put in terms of the other. For another example, like the reduction of lego projects into their constituent pieces, 15 can be put in terms of 3 x 5; said as 3 x 5; characterized as 3 x 5; or explained as 3 x 5. This is all to say that 15 can be reduced or brought back to the more manageable expression of 3 x 5.

While difficult to find antireductionists among mathematicians and lego enthusiasts, reductionism in certain scientific quadrants is more controversial. The weightiness of reductionist talk in scientific theories amasses from their attendant nontrivial ontological implications. That is to say, the style in which we are reductionists may have important consequences for what we say there is. Given certain possible consequences of the countless types of reductionist theses, it is unsurprising that these theses would be contentious. After all, one’s ontology is a precious thing, and certain entities can only very difficultly be rid of on pains of having to reassess the very core of one’s worldview. For instance, if mind is reducible to matter then, barring any reason to think that a numerically identical object could come into being a second time, persons do not survive their deaths.

The pressures or motivations to reductionist thinking are conspicuous. It is obviously enticing to hope for a TOE (Theory of Everything) from which science could explain the full range of empirical data as being reducible to one or just a few very general physical principles or laws. Such prospects are so attractive because they are objects of our shared desire − that for unification. Albert Camus writes, “The minds deepest desire…is an insistence upon familiarity, an appetite for clarity (17).” He continues, “If thought discovered in the shimmering mirrors of phenomena eternal relations capable of summing them up and summing themselves up in a single principle, then would be seen an intellectual joy of which the myth of the blessed would be but a ridiculous imitation (17).”

But if we are scientific realists (that is, if we believe that scientific theories at least approximate the truth of the matter) then in order to justifiably hold on to this dream for unification we must suppose the universe itself to be unified.

Naturalist philosopher of Science Alex Rosenberg calls this the “unity of science” thesis. Science more or less presupposes this thesis in so far as it looks for principles to envelope otherwise fragmented areas of inquiry, i.e. the rather broken disciplines of psychology and neurophysiology.  This thesis, Rosenberg writes, refers to the commitment that, “the reality that the sciences explore is also unified: it consists only in physical things and processes, and combinations and aggregations of them” [emphasis mine] (138).

In connection with evolutionary biology, Daniel Dennett, also a naturalist, writes along a similar vein, “good reductionists think that everything can be explained without skyhooks (82),” where skyhook is an artsy expression for a “‘mind-first’ force or power or process, an exception to the principle that all design, and apparent design, is ultimately the result of mindless, motiveless mechanicity [emphasis mine] (76).”

But notice the emphasis Rosenberg and Dennett give to the mindlessness and physicality of that principle to which all phenomena are to be brought back to. Is this exclusively physicalistic element an essential feature of reductionism? It seems to me it need not be. It seems there is a perfectly intelligible notion of reductionism that is not so unsharedly physical.

It seems to me that reductionism need only preserve this idea of the ‘bring-backedness‘ of all phenomena to some single or very few general principles. Rosenberg has the essential core of reductionism in the first part of the above quote: “the reality that the sciences explore is also unified.” That extra bit following about physicalism is sheer add on. It seems that reductionists need not be committed to the idea that reality is at bottom physical. Rather good arguments should be produced to think that the natural world is, at bottom, solely physical. For instance, naturalist philosopher Thomas Nagel thinks such an exclusively physicalist stance toward reductionism implausible. In a stirring statement offered in the beginning pages of his book Mind and Cosmos Nagel writes, “[certain facts] suggest that principles of a different kind are also at work in the history of nature, principles of the growth of order that are in their logical form teleological rather than mechanistic. I realize that such doubts will strike many people as outrageous, but that is because almost everyone in our secular culture has been browbeaten into regarding the reductive research program as sacrosanct, on the ground that anything else would not be science (7).”

Its seems at least coherent (Nagel would think plausible) to suppose that those few principles into which all other phenomena are to be brought back may share in some form of teleology or intentionality. At least, I hope to have shown how reductionism need not of necessity cast itself exclusively in terms of Rosenberg’s and Dennett’s physicalism.



Camus, Albert. The Myth of Sisyphus. New York: Vintage Books, 1991.

Dennett, Daniel. Darwin’s Dangerous Idea. New York: Simon and Schuster, 1995.

Nagel, Thomas. Mind and Cosmos. New York: Oxford, 2012.

Rosenburg, Alexander. The Philosophy of Science. New York: Routledge, 2012.