The principle of Irreducibility, in philosophy, has the sense that a complete account of an entity will not be possible at lower levels of explanation and which has novel properties beyond prediction and explanation. Another way to state this is that Occam's razor requires the elimination of only those entities that are unnecessary, not as many entities as could conceivably be eliminated. Lev Vygotsky provides the following illustration of the idea, in his Thought and Language:

"Two essentially different modes of analysis are possible in the study of psychological structures. It seems to us that one of them is responsible for all the failures that have beset former investigators of the old problem, which we are about to tackle in our turn, and that the other is the only correct way to approach it.
The first method analyzes complex psychological wholes into "elements". It may be compared to the chemical analysis of water into hydrogen and oxygen, neither of which possesses the properties of the whole and each of which possesses properties not present in the whole. The student applying this method in looking for an explanation of some property of water — why it extinguishes fire, for example — will find to his surprise that hydrogen burns and oxygen sustains fire ....
In our opinion the right course to follow is to use the other type of analysis, which may be called "analysis into units". By "unit", we mean a product of analysis which, unlike elements, retains all the basic properties of the whole, and which cannot be further divided without losing them. Not the chemical composition of water, but its molecules and their behaviour, are the key to the understanding of the properties of water ..."

In other words: to conserve the properties under investigation, it is necessary to remain within a certain level of complexity. Irreducibility is most often deployed in defence of the reality of human subjectivity and/or free will, against those who treat such things as folk psychology, such as Paul and Patricia Churchland.

From Wikipedia under the GNU Free Documentation License
Thu Aug 27 18:20:52 2009

can someone explain to me what is meant by this paragraph? Philosophy?
Q. Jaegwon Kim s causal exclusion argument says that if all physical effects have sufficient physical causes, and no physical effects are caused twice over by distinct physical and mental causes, there cannot be any irreducible mental causes. In addition, Kim has argued that the nonreductive physicalist must give up completeness, and embrace the possibility of downward causation. This paper argues first that this extra argument relies on a principle of property individuation, which the nonreductive physicalist need not accept, and second that once we get clear on overdetermination, there is a way to reject the exclusion principle upon which the causal exclusion argument depends, but third that this should not lead to the belief that mental… [cont.]
Asked by duda7331 - Sat Jun 5 14:52:12 2010 - - 2 Answers - 0 Comments
Beyond Metaphysics and Beyond Wittgenstein...?
Q. Greetings and Salutations: The philosopher Wittgenstein suggests that philosophy's concern with metaphysics is due to bad language. He also suggests that language is irreducible. My question is rather simple, who are some modern philosophers that have responded to this claim, if so who are they? Has anyone ventured past Wittgenstein?
Asked by reverendlovejoy75 - Thu Feb 28 12:22:19 2008 - - 3 Answers - 0 Comments

A. W.V.O. Quine, is (or was... he died a few years ago) a Wittgensteinian. Oh, and Saul Kripke has a lot of stuff about possible worlds and how words denote the same thing in between. Email me if you want more info... Wittgenstein and metaphysics is what I do best. Here is some quick stuff: One way people have responded to this is by saying that language isn't really flawed. Phenominologists say that when we talk we refer to our perceptions, not the metaphysical world beyond them. Other people say that his arguments against reference are just plain flawed. I think Karl Popper was one of his fiercest opponents. Popper thought that we could in fact get metaphysical truth based on scientific probability. You'll have to read more on that… [cont.]
Answered by Adam R - Thu Feb 28 13:46:50 2008

Darwin's theory of evolution and theism rejections?
Q. Hello i'm doin philosophy A lvl at the age of 15 and i need help. i'm struggling to "explain how theists reconcile scientific explanations of the universe with belief in God. I've written about half a page about the 19th-20th century developments in science and the 2 largest challenged theories: Darwin's theory of evolution and hubble's bibg bang theory. i need to know why theism rejects the theory of evolution including things about: Creationism and intelligent design and Irreducible complexity. Can you explain those 2 meanings to mean and explain why? thank you =]
Asked by :) - Sun Feb 22 13:20:15 2009 - - 25 Answers - 0 Comments

A. You need some more study. The Big Bang theory wasn't Hubble's theory -- it was proposed by Georges LeMaitre, a Belgian Catholic Priest. Hubble simply was the first to verify the expansion of the universe, confirming one of LeMaitre's predictions from his theory. Evolution has nothing to do with the origins of life, it simply explains how -- once very simple life arose on earth -- it evolved into the myriad forms we see today. It's an explanation of a process, not a theory of the origin of life. Those religious people who reject the fact of evolution do so because the bible explicity says god created humans in an instant just as they are now, while evolution proves that humans evolved from other animals over billions of years. So the… [cont.]
Answered by WellTraveledProg - Sun Feb 22 13:33:30 2009

From Yahoo Answer Search: "Irreducible (philosophy)"
Sun Jul 11 16:39:33 2010