Last April, Bryce Huebner and I had a Twitter exchange about emergence in biology. I felt that we were talking past each other and tried to work out how it had happened. I suspected that it was due to the way the concept of emergence had been used in different traditions, and I sketched the following tentative history. (I should stress that this is speculative; I’m not a historian.)
1. Late 19th – early 20th century: Some British philosophers (Broad, Lloyd Morgan, Alexander) started using ’emergentism’ to describe a metaphysical view on which the world is radically layered, with new fundamental properties and powers spontaneously appearing at each level, building up to the mental.
2. Mid 20th century: That kind of emergentism was empirically falsified, and philosophers rejected it. However, dualist philosophers continued to claim that some mental properties and powers are fundamental, emerge spontaneously, and exert a ‘top-down’ influence on the physical world, causing particles to behave in ways that physics alone could not predict.
3.Late 20th century: Scientists adopted the term ’emergence’, ignoring its metaphysical baggage and using it in a different sense to characterize global features of complex systems, especially self-sustaining ones. Confusingly, these scientists often spoke of these global features as exhibiting a ‘top-down’ causal influence — meaning that the components of complex systems are causally sensitive to global conditions, not that global features appear spontaneously and exert a fundamental causal influence on the physical world, additional to that of the components.
5. Late 20th – early 21st century: To capture the difference between the philosophical and scientific uses, philosophers drew a distinction between strong and weak emergence. However, they tended to define weak emergence in terms of deducibility and denial of ‘top-down’ influences, which made scientists think that that ‘weak’ emergentists denied the kind of global influences they needed to talk about.
6. Same time: Some dualist philosophers seized on this, claiming that scientists themselves were now talking of strong (spontaneous, fundamental) emergence. If strongly emergent features are common in the natural world, then why shouldn’t aspects of the mind be strongly emergent? Science vindicates dualism!
7. April 2021: Bryce and Keith talk past each other, Bryce adopting the scientific use, Keith the philosophical one.
At the time, Bryce and I talked of writing this up as a short paper, which we may still do. Meanwhile, if anyone has any comments, I’d be grateful for them. Comments from historians of science and philosophy would be particularly welcome!
Hi Keith,
maybe it is easier if we avoid, for a moment, the topics we don’t have a common and good understanding, and try and find stuff we think to understand.
Something I read often is that water is wet. The molecules surely aren’t. So I seems to boil down to fluidity, a certain amount of surface tension, and the tendency to, well, wet a surface (depends on the surface material, of course). This is difficult to compute from molecule date, yet nobody assumes much magic behind it.
Another one is colour. Yet as this is very much dependent from properties of the eye, it may be less suitable.
I’d add the property of “being usable as yarn” (I usually talk about crochetability :-) )
It depends on well understood mechanical properties of material that’s composed out of fibers; whatever they are of – even glass fiber or metal.
These properties can’t be directly seen in the molecules, or whatever the building blocks. Yet they are how we describe the whole thing. If I crochet something, I swirl the yarn back and forth and stuff – does this put force onto the pure molecules? Of course it does, but nothing new for physicist.
Yet rarely anybody uses the physics of molecular bonds to describe yarn; that’s the wrong level.
Kind greetings, z.
Echoing Keith above, I’m interested in how the behaviour of a software system is not explainable in terms of the physics of the hardware.