Anarchism and Naturalism
In the past I have asserted that Anarchism has historically usually dovetailed with naturalistic philosophy and that this is because it is the framework most amenable to shaping Anarchist commitments into a coherent world picture. As I've said the basic reason for this is that Anarchism centers the meaning and understanding of human life in the activity of human social animals within the natural environment. It therefore approaches issues of human knowledge and conduct through the scientific investigation of human society and the regularities of the physical universe. This is what classical Anarchist thinker Peter Kropotkin had in mind when he described Anarchism as a scientific doctrine. In what follows I wish to explore naturalistic philosophy more from an Anarchist perspective including providing a defense for its basic tenets.
Naturalism is the view that nature exhausts reality, meaning that there are no supernatural, or non-natural entities, and that therefore philosophy should restrict its theoretical content to that which is made plausible by the best scientific understanding of the world. Here definitional difficulties immediately arise. We need to have some way of defining "nature" that delineates it from the supposedly supernatural and non-natural. We can easily provide an ostensive definition which lists examples of natural entities and contrasts them with supernatural entities; putting atoms and particles in the natural column and ghosts and Gods in the supernatural column. However, I think we can do better than a mere ostensive definition.
Naturalism is a philosophical outlook that came into its own as a result of the development of modern science. Believers in the supernatural have since the scientific revolution come think of the supernatural as a realm beyond that which science investigates as a result of the fact that science has more and more bracketed questions of the existence of things like ghosts and God off as outside of the domain scientists are interested in. So clearly the natural should be thought of as the proper object of scientific investigation. To say that nature is all there is is to say that if we had a complete scientific theory (that is one that accounted for all scientific data) then we would have an exhaustive description of the world.
The further doctrine of materialism (in contemporary anglophone philosophy it is called 'physicalism') can then be understood as the version of naturalism which asserts that if we had a complete theory of physics we would have an exhaustive description of the world. A supposed problem for this definition is known as "Hempel's dilemma" related to the philosopher Carl G. Hempel. The dilemma is that if we define the object of scientific investigation in terms of current scientific theories then naturalism will be false given that those theories are incomplete. If we define it in terms of ideal (complete) theories then supposedly naturalism becomes trivial (vacuous) because we don't yet have ideal theories and thus purportedly have no idea what they would appeal to.
Naturalists should probably concede that neither the current, or ideal theory horns is good enough for defining their view. Instead they should resist the assertion that they are bound by the horns of the dilemma in view of a third alternative. The actual development of scientific theories over historical time is what informs us about the kinds of things science investigates. We think science investigates the chemical make up of objects because of the development of scientific chemistry. Likewise we don't think science, at least in any straight forward way, investigates the existence of demons because the scientific community has moved systematically away from such questions in its research. So when the naturalist says that all that exists is natural they are saying that only the objects of scientific investigation exist and we know what those objects are by taking a look at the actual development of scientific theories.
With naturalism defined we should move to the issue of why we should be naturalists. The argument for naturalism at its most basic is the development of the scientific worldview. Naturalists believe that the scientific worldview provides strong evidence for conceiving of nature as independently an existent casually closed totality which subsumes all real processes and properties. The basic argument proceeds in the following way:
If all phenomena that have explanations have scientific explanations than the natural exhausts reality.
All phenomena that have explanations have scientific explanations.
So the natural exhausts reality.
The key premise is obviously the second one. Why should we believe it? Here we appeal to the sheer scope of scientific progress in the last 500 years. We have developed scientific theories of the expansion of the universe, creation of solar systems, diversification of life on earth, and the dynamics of human character and social development. This process has systematically replaced supernatural explanations such as divine intervention, special creation, disembodied consciousness, demonic intervention, ect. Thus the modern world picture is disenchanted compared to it's ancient and prehistoric counterparts.
In premodernity human life was dominated by natural cycles as well as local traditions and thought patterns. Having little understanding of how the natural forces involved worked human beings imagined powers that transcended the regularities of the everyday realm they corporeally interacted with which worked in similar ways to the entities and regularities within the latter, especially transcendent entities with the attributes of agents (beings that act and choose) since the entities they were most familiar with were themselves as agents. These powers did everything from establish and overthrow kingdoms, teach humans mores and skills, create features of the ecological environment, and even create the world itself. In the modern world the development of capitalist industry required the development methodologies reliant on regularized, standardized, empirical observation for understanding nature (obviously industry could not rely on divine favor).
Thus the modern world picture is one in which nature mechanistically operates according to its own internal regularities without any necessary reverence for human purposes. This is what Nietzsche referred to as the death of God. After God's death even those who do believe in the transcendent (in the sense of the supernatural) find it hard to do so. The divine realm has a tendency to retreat beyond nature even further and directly intervene in it and thereby directly evidence itself in human life less and less.
While the death of God creates a bona fide crisis of meaning as it forces traditional reservoirs of meaning to evaporate, in doing so it creates the possibility of a new type of meaning for humanity. This new type of meaning is humanistic and scientific. Human beings can see themselves as rational social animals who, despite being coerced by mechanistic natural processes, can develop new social relations to themselves and nature that allow human beings to understand and thereby transform nature so as to continually extend human life and happiness and thereby reduce nature's coercive pull on humanity. Thereby the door is upon for a naturalistic worldview which does away with all powers above humanity as nature conscious of itself.
This is where a distinction has to be made between the kind of naturalism Anarchists advocate and the typical naturalistic philosophy on offer in analytic philosophy departments. In the 20th century academic philosophy was split into two great camps; analytic and continental. Analytic philosophy claimed that the right way to answer philosophical questions was the apriori (before experience, or from the armchair) analysis of concepts using formal mathematical logic. Thus analytic philosophy became dominated by a type of naturalism which asserted that the place of philosophy relative to science was simply to disentangle concepts so that they could be used properly in scientific domains.
While all forms of naturalism tie philosophical theorizing to scientific evidence analytic naturalism divorces philosophy of critical theoretic content. That is philosophy has always been an avenue by which the human condition could be examined and from that examination a description of the good life could be deduced. In the modern world political philosophy took on an ideological character where the development of mass movements and mass political agency facilitated the application of philosophical theorizing to the question of how society should be transformed. However, despite the fact that analytic philosophy gave rise to many developments in political philosophy since WW2 its methods, even in political philosophy, presuppose the categories of the socially dominant modes of thought (whether from economics, political science, sociology, psychology, or anthropology) as pre-theoretic raw conceptual material to be clarified by conceptual analysis and then utilized by science.
As such most of political interest in analytic philosophy has been argued from the centrist liberal/conservative perspective that has been geoculturally dominant within the capitalist world-system since 1848 and most analytic philosophy consists in constant back and fourth over the same ancient and early modern arguments (e.g. the ontological and cosmological arguments for God's existence, Cartesian and Pyrrhonian arguments for skepticism, arguments about the reality of abstract objects such as numbers, sets, propositions, and properties, and arguments over the "mind-body problem" concerned with how consciousness emerges from matter and how free will is possible within the scientific world picture). By contrast continental philosophy which methodologically focusses on social science, culture critique, history, and interpretation has produced numerous critical theories aimed at showing how existing modes of thought are produced by the capitalist world-system and can have their limits transcended via the transition to a more just society (the name critical theory was coined by continental thinkers associated with the Frankfurt School of Social Research). As such, despite the dominance of naturalism within the analytic tradition since its beginning, conceptual challenges are constantly mounted to it, whereby in the continental tradition it is simply the working assumption of most theorists who aren't writing in its explicitly spiritualist incarnations.
As such Anarchistic naturalism must be of the continental, rather than the analytic variety. This isn't to say that Anarchists reject all analytic philosophy out of hand. In fact the first programmatic step to helping philosophy out of the analytic clap trap is promoting interaction among both analytic and continental traditions to break down the methodological iron curtain between them. It is rather to say that Anarchism should always retain its critical theoretic posture, with its naturalism being no exception.
Sources
Modern Science and Anarchism, Kropotkin
Continental Philosophy, Critchley
https://plato.stanford.edu/entries/critical-theory/
https://iep.utm.edu/critical-theory-frankfurt-school/
https://iep.utm.edu/naturali/
https://plato.stanford.edu/entries/naturalism/
Understanding Naturalism, Ritchie
Continental Philosophy of Religion, Burns
https://plato.stanford.edu/entries/liberalism/
https://plato.stanford.edu/entries/conservatism/
World-Systems Analysis: An introduction, Wallerstein