The idea of theory-ladenness became popular in the 1960s, and has remained popular in various sections of academia ever since. It’s often said to have begun with the work of Kuhn, Hanson and Feyerabend in the late 1950s. This idea impacts on science, and is said — by some — to lead to “anti-science”, “relativism” and “the attack on objectivity”. Whatever the case is, scientific theory is obviously distinguished from observation. So are all observations theory-laden? Just some? Or is it more a question of degree? The following essay relies on the work of the philosopher of science Ian Hacking, whose position is nuanced. Hacking sees the truth in much of what Kuhn, Hanson and Feyerabend argued. Yet at the same time he stated that “[t]here have been important observations in the history of science, which have included no theoretical assumptions at all”. Hacking also argued that the overuse of the term “theory-loaded” effectively made it “trifling”.
Philosophical positions on the distinction between observation and theory range from the old “naïve” view (i.e., that scientific observations must be pure) to rejecting the distinction altogether. Many philosophers take a position somewhere down the middle, but even that middle has various grey areas.
The philosopher Ian Hacking took a nuanced position that’s partially against some distinctions between theory and observation, but one which questions the complete rejection of the distinction too.
What is original to Hacking is his stress on experiment, which he believed had been largely ignored by philosophers. More relevantly, we had the distinction between observation and theory, but now we have Hacking’s idea that “[e]xperiment supersedes raw observation” too. It may be a surprise to some that Hacking simply inverts this particular binary opposition. Perhaps there’s little point in saying that observation supersedes experiment or that experiment supersedes observation.
N.R. Hanson and Paul Feyerabend
The fixation on theory-ladenness at least partly began with the philosopher N.R. Hanson. In his 1959 book Patterns of Discovery, he came up the with the term “theory-loaded”, which in subsequent years became a bit of a cliché. Hanson argued that every sentence and term is theory-loaded.
Many of Hanson’s examples are convincing. However, is what is drawn from them legitimate too?
The American philosopher of science Dudley Shapere adds to Hanson. In his case, however, it’s the nature of scientific devices which concerns him. Hacking states that Shapere
“ makes the further point that physicists regularly talk about observing and even seeing using devices in which neither the eye nor any other sense organ could play any essential role at all”.
It can be said that there’s no serious problem with scientists using everyday terms in their own non-everyday work. Why shouldn’t they use the words “observing” and “seeing”? What’s more, it can be doubted that many scientists will be troubled with the quibbles philosophers have with their using these words.
Feyerabend went further than Hanson and Kuhn.
In his 1977 book Against Method, he argued that the observation-theory distinction is bogus. In other words, all scientific observations are always theory-laden.
Some readers may now be wondering what exactly Feyerabend meant by “theory”. (This is true about many other uses of that word too.) Hacking picked up on Feyerabend’s use of the word when he wrote the following:
“Unfortunately the Feyerabend of my quotation used the word ‘theory’ to denote all sorts of inchoate, implicit, or imputed beliefs.”
The word “theory” is often thrown around like confetti. Thus, on Hacking’s reading of Feyerabend’s position, one doesn’t need to express one’s theory explicitly, or even know that one has a theory in the first place. In addition, it’s often not the case that a person has a theory “behind” his words or statements: it’s that other people believe that he has. So a theory can be vague, unexpressed and projected onto others.
Despite all that, Feyerabend still believed that theoretical assumptions underlie
“the material which the scientist has at his disposal, his most sublime theories and his most sophisticated techniques included, is structured in exactly the same way”.
Now an everyday cliché can be used:
If everything is classed as a theory, and if theories can be found in every statement or term, then there are no theories at all. The word simply ceases to have any point.
Hacking agrees:
“Of course if you want to call every belief, proto-belief, and belief that could be invented, a theory, do so. But then the claim about theory-loaded is trifling.”
Hacking wrote the following too:
“Of course we have all sorts of expectations, prejudices, opinions, working hypotheses and habits when we say anything. Some are contextual implications. Some can be imputed to the speaker by a sensitive student of the human mind.”
Did Feyerabend really include expectations, prejudices, opinions and habits under the catchall term theory? Indeed, can’t we have expectations, prejudices, opinions and habits and it still not be the case that what we say (or everything we say) is theory-laden?
Hacking: No Theories At All
Oddly enough, although the theories-are-everywhere idea can easily be criticised, Hacking’s own position seems odd too, at least at first. He continues:
“There have been important observations in the history of science, which have included no theoretical assumptions at all.”
Following on the what was said a moment ago, it can be provisionally accepted that these important observations included no theoretical assumptions at all. Yet, at the very same time, the people who made them were (well) over-laden with expectations, prejudices, opinions and habits…
So what?
Hacking’s position may even strike a scientific realist as being extreme. Just for one. Why were such scientists making their important observations in the first place if they were completely free from theoretical assumptions? Of course, we’ll need to see examples here. Hacking, being an historian of science [see here] as well as a philosopher of science, cites plenty.
To ram the point home. Hacker argued that “[t]here are plenty of pre-theoretical observation statements, but they seldom occur in the annals of science”. Just to remind readers. Hacker took a fairly strict position on what a scientific theory is, whereas someone like Feyerabend was very loose with the term.
Logical Positivists and Quine on Observation
Feyerabend was largely reacting against logical positivism. [See here.] Hacking puts the positivist position at its most extreme when he tells his readers that the
“positivist, we recall, is against causes, against explanations, against theoretical entities and against metaphysics”.
More clearly, “The real is restricted to the observable.”
All this depends on what “the real” means. If it means observable, then that statement is true by definition. Of course, the core of the planet Earth can’t be observed, and neither can distant planets and quarks. What about numbers? Positivists had various answers to some of these examples, but not to all.
To run through Hacking’s list. Being against causes is a Humean position. Obviously, causes can’t be observed. Constant conjunctions can be observed, but not the nature of the cause itself. To be honest, I can only guess at what “against explanations” means. Is the argument that if you rely exclusively on observation, then you don’t need explanation too? The case against metaphysics is obvious from a positivist and observation-based point of view.
Now take Hacking’s criticisms of W.V.O. Quine’s position, which stresses not observations, but “observation sentences”. Quine, as quoted by Hacking, states that we should “drop the talk of observation and talk instead of observation sentences, the sentences that are said to report observations”. Hacking had a problem with Quine’s distinction (observations vs observation sentences) within another distinction (observation vs theory).
Hacking stated that Quine was “quite deliberately writing against the doctrine that all observations are theory-loaded”. Quine articulated this position in his 1974 book The Roots of Reference. That was long after Kuhn, Hansen and Feyerabend had first articulated their own controversial theories. As many readers will know, the critics of Kuhn and Feyerabend focussed on their “relativism”, rather than their stress on theory-ladenness. Of course, these two issues have been intimately tied together.
The first thing that can be said here is that Quine’s observation sentences simply seem to be proxies for… well, observations. And Hacking’s general point against Quine is that his theory of observation sentences is just as naïve as some talk about (mere) observations. So Hacking clarifies Quine’s position, which is essentially communal in nature.
Quine believed that “observations are what witnesses will agree about, on the spot”. That’s a non-scientific (or non-academic) three words to use: “on the spot”. Still, Quine provided details. He argued that
“a sentence is observational insofar as its truth value, on any occasion, would be agreed to by just about any member of the speech community witnessing the occasion”.
What’s more, “we can recognise membership in the speech community by mere fluency of dialogue”.
So we have these everyday utterances from Quine: “on the spot”, “just about any member of the speech community”, etc. But let’s remember here that Quine was a pragmatist of sorts. [See here.] So why shouldn’t he have been imprecise on these matters and simply focussed on his own self-referential observation sentences about how communities use words and sentences.
Hacking too has a problem with the above. He stated that “[i]t is hard to imagine a more wrong-headed approach to observation in natural science”. His main argument, at least at this point, was against Quine’s stress on the community. He cited the case of Caroline Herschel, the wife of William Herschel:
“No one in Caroline Herschel’s speech community would in general agree or disagree with her about a newly spotted comet, on the basis of one night’s observation. Only she, and to a lesser extent William, had the requisite skill.”
This seems to go against any notion of communal truth. Alternatively put, it shows that truth can be arrived at independently of any community.
Various communal ideas about truth and knowledge can be dated back to Wittgenstein [see here], as well as before, and Quine was much influenced by him. [See here.] Hacking’s own stress was different. The last two words, “requisite skill”, are important here. In the community of the late 18th century there wouldn’t have been many — if any — people with same skills as Caroline Herschel. But did she or didn’t she discover eight new comets? Yes she did. [See here.] Yet she didn’t need — or rely on — any community to do so, except in less direct and rather obvious senses. In other words, Herschel needed the traditions of science, the devices of science, to share a natural language with various communities, etc. However, none of this is directly connected to Herschel discovering comets, and the knowledge she gained by doing so.
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