Scientific Realism

🔬 philosci

Science is trying to describe the world. In terms of Plato, is there a real world out there (a mind-independent reality)? Does nature have 'joints', and can science carve those joints?

The traditional view of scientific progress is often termed "scientific realism." Scientific realists believe that science progresses by accumulating knowledge that increasingly corresponds to the true nature of reality. According to this view, scientific theories become more accurate over time, and scientists get closer to the truth as they build upon previous knowledge .

Anyone who says yes to the above is a scientific realist and not a scientific antirealist. It is a binary option.

Key Attributes of SR

1. Cumulative Knowledge : Scientific knowledge builds cumulatively, with new discoveries adding to or refining existing knowledge.

2. Correspondence to Reality : Scientific theories aim to describe and explain the natural world accurately, and they get closer to the truth over time.

3. Objective Progress : Scientific progress is seen as an objective process, where later theories are better than earlier ones in terms of explanatory power, predictive accuracy, and coherence with empirical data.

Variations of SR

Hard realism: There are real differences/similarities that we can learn. There is a single way the world is, and science's goal is to find that, primarily through 'natural kinds' such as the periodic table of elements.

However, the vast majority of scientific work is not necessarily dedicated to finding these 'natural kinds.'

Soft realism : There are real mind-independent things, but the differences/similarities are determined by our interests. For example, 'Jade' is real in the natural world, even though it's not a 'natural kind', but composed of two minerals (jadeite and nephrite, which look indistinguishable to the naked eye). Science should care about taking the interests of the scientists into account. Its goal is to organise the mind-independent world in a way that makes sense to humans.

However, the problem is that much of what scientists are interested in has no clear basis in the world. For example, 'species' or 'genes' are vague but very useful.

Current realism: Reality is more or less the way out, as best scientific theories say it is. This is the most common view accepted by realists. These recent theories are the best because they have survived rigorous testing, e.g., Popperian falsificationism.

However, the problem that Van Frasen argued is that if current theories are wrong, then realism is also wrong. Godfrey Smith also agreed with this.

Common sense realism (Naturalised) : Developed by Godfrey Smith, who was both a naturalist and a realist. We all inhabit a common reality, which has a structure that exists independently of what people think of it, insofar as reality is affected by our thoughts in ways that are uncovered by science.

However, we have seen that science and common sense do not go well together when examining the history of science, e.g. geocentrism.

Other variations:

- Entity realism : We should believe in the entities that are described by the theories but be sceptical of the theories themselves. Philosopher #ian hacking said that if we can manipulate entities that they ought to exist, "If you can spray them, then they are real."

- Structural realism : Opposite of entity realism. We should be sceptical of the entities themselves, but be confident in the structure of the theories. Essentially, this was demonstrated in 1862 when Frenchman Louis Pasteur proved that bacteria can only evolve from existing bacterial cells and not from inanimate matter. The chemist developed and pioneered the procedures of disinfection, sterilisation and pasteurisation. His idea of 'chromes' as the entities that were responsible for the disease was not correct.

For these reasons, scientific realists usually restrict their views to mature theories:

Mature theories have:
- been around for a while
- been rigorously tested
- attained a consensus amongst the scientific community

This means that realists are very cautious of new emerging theories such as string theory or dark matter. However, scientific realists believe that most of the mature theories are true, such as Newtonian mechanics of photons, and they will tend to be more true over time.

Notable Proponents of SR

- 🔬 karl popper : Advocated for the idea of falsifiability as a criterion for scientific progress.

Where is the debate?

Claims we make make references to entities. Entities can be split between:
- observables : entities that can be perceived with unaided senses
- unobservables : entities that are detectable only using special instruments

Science always tries to make claims about the observables. There is very little debate between anti-realists and realists on the matter of claims made about observables, unless for the extremist philosophical sceptics detailed below.

Scientific realism is a common-sense view of the world. The (scientific) realist argues that we can even make perfectly valid claims about unobservables because of scientific tools. The reasoning is simply that, observables and unobservables exist in the same manner. It is assumed that when we reference unobservable entities, they do, in fact, exist, that they do comprise the physical makeup of the world and that we interact with them even though they are not directly able to be perceived by us.

Presumptions about Unobservables

The issue rose to prominence when many past scientific theories have been proven wrong, and many entities postulated by scientists did not exist. For example:
- miasma theory of disease (diseases thought to be caused by poisonous air)
- caloric theory of heat
- phlogiston theory of combustion (thing released from air during combustion)

For a more nuanced discussion on the issues of theoretical entities, see the dichotomy and status of theoretical entities .

Philosophical Commitments

From 🎓 james ladyman - UPoS 5.5 :

scientific realism involves three kinds of philosophical commitment:
- metaphysical commitment (metaphysical modesty of ontology) to the existence of a mind-independent world of observable and unobservable objects;
- semantic commitment to the literal interpretation of scientific theories and a correspondence theory of truth (theories should be taken literally and can be either true or false)
- epistemological commitment (epistemic immodesty) to the claim that we can know that our best current theories are approximately true and that they successfully refer to (most of) the unobservable entities they postulate, which do exist.

Contrasting Views

To recap, scientific realism says there is a mind-independent reality, theories can be construed for both observables and unobservables, and all of these theories give us knowledge.

- Philosophical scepticism : agnostic about mind-independent reality, theories are construed literally, but they DO NOT give us knowledge. We can't know that even objects like trees or cars exist.
- Crude Instrumentalism : there is mind-independent reality. Observables exist and we can make claims about them, e.g. this table exists, but we cannot claim anything about unobservables. So theories based on observables give us knowledge, but ones based on unobservables do not.
- Logical positivism : existence of mind-independent reality is meaningless. Any question that can't be answered using empirical questions is useless. Theories cannot be construed literally about observables or unobservables, but they do give us knowledge because changes in empirical data can be observed which give us some indication of how the world is. Logical positivists don't like talking about theoretical entities. They say if you cannot reduce theoretical entities to observable ones, it is useless to talk about them in any scientific way. The issue of distinguishing between observable and unobservable entities was raised against logical positivists - sometimes, we mistake unobservable entities for observable ones.

- Constructive empiricism : There is a mind-independent world; theories can be construed literally, but science does not give us knowledge about observables. The point of science is empirical adequacy. The only requirement for this is that theories are correct based on if we can empirically verify their phenomena. This is very plausible.

Notable Antagonists

- 🔬 thomas kuhn ( social constructivism ): His concept of "paradigm shifts" and "incommensurability" challenges this traditional view by suggesting that scientific progress is not always cumulative and that different paradigms are incommensurable both in terms of what we actually make of the real world - reference (metaphysical) incommensurability as well as method (epistemological) incommensurability meaning they cannot be directly compared in terms of truth or accuracy. So, you cannot talk about any reality outside of the context of a paradigm. On this note, Kuhn rejects the notion of semantic commitment (theories cannot be taken literally due to meaning (semantic) incommensurability . Kuhn's rejection of semantic commitment highlights his position that scientific theories are not simply reflections of an objective reality but are constructed within specific paradigms. Kuhn famously said, "when paradigms change, the world changes, " which is metaphysically immodest.