Dr Gregory Farrelly FAITH MAGAZINE July-August 2013
Science and Religion News
In a talk to the Faraday Institute in Cambridge, George Ellis FRS, professor emeritus of applied mathematics from Cape Town University, offers an interesting analysis of reductionism. The talk, entitled “Emergence, Top Down Causation and Reductionism”,
is available at http://sms.cam.ac.uk/media/1472806. Be warned, though, that Ellis tends to read his presentation slides verbatim rather quickly, making it hard to digest what is said.
His aim is to show that the prevalent scientific reductionist methodology is invalid. In reductionism, lower levels of reality determine completely the higher levels; thus higher levels are “epiphenomena”. As an example, he quotes Francis Crick as saying that our “… sense of personal identity and free will are in fact no more than the behaviour of a vast assembly of quarks and electrons.”
Ellis points out that this is not a viable explanation since it claims that a particular level (of reality) is the only real one, whereas causal power exists at every level. He makes the point that contextual effects in nature and in computing are such that higher levels affect lower levels in a co-ordinated way.
In fact, higher-level variables control and constrain reality such that the lower-level realities are changed. He gives the example from biology that it is the mind that controls physiological events such as walking: the mind controls the chemicals involved, and thus the decision to walk affects the electrons when you move your foot.
DNA coding is affected by the environment via adaptation; DNA specific structure is unpredictable from biochemistry/physics alone but is environmentally determined over generations (via natural selection) –resulting in the white fur of the polar bear, for example.
In another example, he uses the example of human vision: the cortex predicts what should be seen and the mind fills in the gaps; in other words interpretation takes place according to expectation, so context even changes the way that neurons function.
Ellis has been particularly impressed by the way that computer programs work. The software is abstract, unlike the hardware, and can be written in many different ways at a lower level (machine code). This is clearly a top-down analysis. Here, the abstract algorithms have causal power, not derivable from physics alone. The problem to be considered, then, is: how can physical systems that are determined from the bottom up show top-down behaviour?
He points out that the human mind must be something like the computer in its interrelated hierarchy of levels from application software down to machine code, yet the mind is not itself a mere computer. Although the bottom-up approach can be successfully applied, as in the kinetic theory of gases, this is not the case in general in nature. Biological cells begin as pluripotent (as in stem cells, discussed below). Then they become specialised: an example of top-down interaction in which context determines development. Top-down selection leads to increased complexity, enabled by the randomness of lower-level processes, an intriguing thought.
This should all sound rather familiar to readers of Faith magazine. The Unity-Law of Control and Direction in matter is such that there is an interdependence of being, forming a unique and dynamic ecosystem, from subatomic particles up to the human person.
As Ellis states: “No real physical/biological system is really isolated.” When he says that the higher levels are more causally “real”, the Catholic philosopher may well recall the concept of the analogy of being, which we have mentioned in this column and elsewhere in previous issues of the magazine.
After 15 years of failed experiments, a cloning breakthrough was accomplished by scientists at Oregon University recently. DNA was taken from a human patient and spliced into a human egg that had had its DNA removed. The egg then grew into an early-stage embryo whose stem cells, a genetic copy of the original, were then harvested.
Stem cells can transform into any other human cells, so they have immense potential for generating all sorts of adult cells and thus can be used in research concerning human degenerative (and other) diseases. The Oregon scientists used a variation of the technique pioneered in the cloning of Dolly the sheep, using electric pulses to stimulate the unfertilised eggs to start dividing. This technique can be contrasted with the use of induced pluripotent (iPS) cells, which have all the properties of embryonic stem cells but are not produced from embryonic cells.
The scientific question is whether embryonic stem cells produced with the Dolly method are superior to those created with the iPS method. iPS cells tend to age prematurely and die; they are also created with cancer-causing genes, which could make them dangerous to use therapeutically. Another possible advantage of using the Dolly method to produce embryonic stem cells is that it takes just days, compared with weeks for iPS cells.
For me, this is a clear example of the end not justifying the means. Life begins at conception; thus the destruction of blastocysts (groups of embryonic cells) is intrinsically wrong. Stem cell research is perfectly permissible: it concerns helping the living; but embryonic stem cell research is about destroying some of the living, namely those who are still young and vulnerable as embryos. Once again the importance of a sound metaphysics and moral philosophy is evident; philosophy, science and theology
really do affect us all.