§67. The Experience of an Experiment

Experience in Carnap's empiricism is anonymous and de-subjectified. He gives this example of a protocol sentence, reporting the ultimate empirical data of science: “Here now pointer at 5, simultaneously spark and explosion, then smell of ozone there” The protocol is supposed to be pure observa­tion, devoid of theoretical terms.

Experimenters are meta-meters, meters reasoning on other meters, which they apparently accomplish without collegial interaction in a research envi­ronment. However, there is a good deal more for experimenters to do than register protocols. They have to be good at using them, which takes more art than reading a meter. Experimenters use observations to calibrate their devices, persuade their colleagues, and test apparatus for artifacts; without facility in these tasks uttering “pointer at 5” is to no avail. A physicist and philosopher of experiments writes, “Experimental culture is grounded in expertise—the ability to eliminate kinds of backgrounds and an instinctive familiarity with the valid limits of an apparatus.” Carnap might shudder, but that is an insight into scientific practice and suggests how much Carnap ignores about real science.¹⁵⁹

To work productively in science requires experience, not because perceptions are ultimate evidence, but because experiments and their equip­ment cannot be fully automated or measurements mechanized.

As a participant-observer in bacteriologist August Wassermann’s labora­tory, Fleck observed the variety of skills among his colleagues; for instance, preparing uniform dilutions of organ extracts, measuring and storing sera, and washing vessels, with the best technicians also having what Wassermann called a “serological touch.” Touch was also invaluable to the interferometer devised by Albert Michelson to search for evidence of the ether. His appa­ratus was commended as “a wonderful instrument if operated by Michelson” It took his trained eye and hand “to sense when that momentary jitter in the image, barely noticeable to other optical experts, was grounds for dismissing the run.”¹⁶¹

Astronomer John Herschel observed that “an object is frequently not seen from not knowing how to see it, rather than from any defect in the organ of vision.” Repeatedly in the history of telescopic observation some new feature is eventually made out—a third Saturnine ring, moons of Mars, exoplanets— then found to be observable by smaller devices, with observers declaring the feature easy to see. Why was discernment delayed? One observer suggested that Saturn's rings had grown more luminous, but the reason seems to be the one Herschel mentioned, which is that observers did not know how to see the new objects. Merely being able to see, say, antibodies or Martian moons requires experience. The ability to perceive a form—see it, name it, confirm it—is acquired only with much memory, the trials of experience.

Fleck thinks all really valuable experiments are uncertain, incomplete, and unique. “When experiments become certain, precise, and reproducible at any time, they no longer are necessary for research purposes but function only for demonstration.” Fleck's rule of thumb is, “the more unknowns and the newer the field of research, the less well defined are the experiments”; if a research experiment can be well defined it is unnecessary to perform it. Galileo's effort to determine the constant of gravitational acceleration is probably the first deliberate effort at experimental measurement. He discov­ered the problem's difficulty, and invented ways to approach it; for instance, substituting an inclined plane for vertical freefall (which was not his inven­tion, as the telescope was not, only what he made of them was new). It takes experience to navigate the problems experimentation poses, and develop a touch for methods and apparatus.¹⁶³

Experimental objectivity is not a method but an achievement, a work of art. Isabelle Stengers defines it as “the creation of a rapport authorizing the definition of an object.” What she calls the experimental invention is “the invention of the power to confer on things the power of conferring on the ex­perimenter the power to speak in their name.” By a successful experiment we confer on its apparatus and methodology the power to confer on those who use them the power to say what nature is. Stengers's idea complements Bruno Latour's thought of experiment as a trial, passing through which changes everything that interacts under its auspices.

Latour describes an experiment as an “event,” a philosophical usage inflected by Whitehead. What is event-like about an event is movement with continuity; an event is a happening, but the happening happens in an interval of continuous change. It is in the quality of this movement that we have to look for the accomplishment of an experiment. Every experiment is at once the ancestor of future experiments and the culmination of antecedents. What is decisive to the advance of science is not the experiment in isolation but the difference between experiments in a series that defines a learning curve and expresses the cognitive quality of the cumulative experience. To describe an experiment as an event therefore implies the historicity of all its factors. Historicity means having been changed by effects peculiar to the passage of time, which does not merely pass but transforms. Nothing is the same before and after the experiment—not nature, not society, not the experimenters, not the past, or the future.¹⁶⁵

C. S. Peirce had a lot of experience with experiments, and knew it was a mistake to regard observation and measurement as passive. Inserting a probe always has a disturbing effect, and only systematic experiment can isolate a signal from the sea of noise. Tuning in, silencing the background, and iso­lating artifacts are the ordinary challenges of laboratory life. According to Peirce’s pragmatic maxim, to elucidate the meaning of a term, one has to explicate the experimental phenomena it predicts. What he calls a term’s rational purport “lies exclusively in its conceivable bearing upon the con­duct of life.” If one “can define accurately all the conceivable experimental phenomena which the affirmation or denial of a concept could imply, one will have therein a complete definition of the concept and there is abso­lutely nothing more in it.” There is always something experimental about experience, and something experiential—perceptual, compulsive—about experiments.

Why not pursue natural science as Hobbes did? “I do not here examine things by sense and experience but by reason.” Why seek the actual mech­anism, how nature actually goes, and not a merely possible one deduced from rational principles with no counter-evidence? To know how nature goes you have to observe and experiment, but no observation or experiment will tell you how nature goes. The best proof of experimental conclusions is that we can use what we observe and measure to enlarge our power of action. Here is the difference between Aristotle and Hobbes on one side and Galileo and Bacon on the other. Aristotle and Hobbes anticipate no instrumental boon from natural philosophy, whereas Galileo and Bacon do. Their model of knowledge is not Hobbes's Aristotelian one. It is that of a medical empiricist, a sophisticated one like Galen, using the method of analysis and synthesis as geometrized in Alexandria, and with a Hippocratic expectation of prog­ress in natural knowledge. Natural philosophy should be more than a system of concepts, as medicine has to be more than a theory, and like medicine natural philosophy requires more than logic or reasoning from principles. It has to accomplish something logic alone cannot do, which is to enlarge our power of action.¹⁶⁷

The Marburg neo-Kantians and the Vienna positivists want to have sci­ence without sensory intuitions. Ernst Mach, carelessly classified as a posi­tivist, refused to follow this line, insisting (as did Poincare) on the value of sensory intuition in scientific epistemology. He explains intuition as “the whole system of spatio-temporally ordered sensations which enables us for example to recognize at a glance the whole disposition of bodies or their rel­ative motions.” He pays tribute to “the close conjunction of thought with ex­perience,” which, he says, “has built modern science.” “All intellection starts from sense perceptions and returns to them,” and “wherever it is possible to strengthen conceptual thought by intuition, this will happen with profit.”¹⁶⁸

Mach saw no important distinction between a normally functioning nervous system capable of memory and learning and a scientifically organ­ized experiment.

Mach's idea of an experiment is simply to control changes and watch for invariance. Artificially hold something still and look for co-invariants. That we disturb any system we measure or even just observe does not have to be a crisis. It depends on how we understand successful inquiry. Is it enough when we can make out the invariants of experience, hypothesize their law, and make testable predictions? Or must we attain knowledge of essence, the things in themselves? If perceptual invariants reduced to law are enough for science, then experimental interference is a useful thing to do. Experimenters make their disturbance and watchfully await a response, keeping a careful re­cord. Experiential experience is much memory of such trials, learning by ex­perience how to discern signals of invariance amid nature’s noise.

Mach’s understanding of experiments makes them continuous with evolved perception; for it is not only in experiments that we perceive invariants. We are neurologically tuned by evolution to attend to the invar­iant in all sensory modes. To look into this further requires a digression on theories of perception.