Limits of Science?. John E. Beerbower
The term “gene” was not used by Mendel. The concept was set out by Dutch botanist Hugo de Vries in 1889 (an inheritable unit that caused a specific trait, which unit he called a panagene). The word “gene” was introduced in 1909 by Danish botanist Wilhelm Johannsen. See “Gene” (revised 2009), The Stanford Encyclopedia of Philosophy.
10 I use “inductive inference” here in the common, lay sense of drawing at least tentative inferences from the observation of apparent patterns or regularities in events. The philosopher’s “problem of induction” is discussed at some length in the next section of this chapter.
11 The editor added a footnote there explaining that Hume used the word “science” in the pre-nineteenth century sense of knowledge or learning generally.
12 Hume used “knowledge” to refer to pure mathematics or pure deduction, things known from “first principles.” Understanding of the physical world came from (and with) probabilities and was referred to by Hume as “opinion.” Any theories about cause and effect in the physical world were necessarily of the latter type. See Ian Hacking, The Emergence of Probability, pp.180–1.
13 Hume goes on to characterize inductive reasoning in a rather pejorative manner. He asserts that the inductive inferences from experience are the mere result of “custom or habit.” “There is some other principle which determines him to form such a conclusion [that the future will resemble the past]. This principle is custom or habit.” Id., p.43. “All inferences from experience, therefore, are effects of custom, not of reasoning.” Id., p.44. “[A]fter a repetition of similar instances, the mind is carried by habit, upon the appearance of one event, to expect its usual attendant [the apparently related event], and to believe that it will exist.” Id., p.69. “Our idea, therefore, of necessity and causation arises entirely from the uniformity observable in nature, which similar objects are constantly cojoined together, and the mind is determined by custom to infer the one from the appearance of the other.” Id., p.75.
14 Probability is not an unambiguous concept. Rudolf Carnap argued that there is concept of “logical probability” or “inductive probability” that reflects the confidence we can have in a particular theory or proposed law of nature in light of certain evidence—i.e., that reflects the likelihood that the law is true or the degree of confirmation provided by the evidence. He contrasted this concept with the more familiar concept of “statistical probability.” See Rudolf Carnap, Philosophical Foundations of Physics (Basic Books, 1966), pp.20, 34–5. This subject is discussed further in the chapter on Mathematics.
15 John Stuart Mill used the concept of causality or causal inference to explain the essence of inductive reasoning in his book A System of Logic (1904). See Peter Lipton, Inference to the Best Explanation, pp.18–19. An inference of causality was justified where all known cases of B were preceded by A or where there is only one identifiable difference between similar situations in which B occurs and those in which it does not (e.g., the presence of A). Id.
16 Foresight and understanding necessarily involve a fundamental subjective element, that is, they incorporate or turn upon the mental process of comprehension. The concept of explanation also, of course, implicates mental processes, and even prediction presumes more than a mere passive observer. We will return to these issues, but I would like to minimize their role for the present discussion.
17 Deutsch explains that “[o]ne cannot make even the simplest prediction without invoking quite a sophisticated explanatory framework.” Id., p.15. Testing and measurement techniques themselves depend upon theories of testing and measurement. Id., p.317. “The very idea that an experience has been repeated is not itself a sensory experience, but a theory” because “we are tacitly relying on explanatory theories to tell us which combinations of variables in our experience we should interpret as being ‘repeated’ phenomena in the underlying reality, and which are local or irrelevant.” Id., p.7. For a detailed discussion of the impressive scientific achievements made and their contribution to the advancement of science involved in developing accurate measurement techniques in one particular area (thermometry: the measurement of temperature), see Hasok Chang, Inventing Temperature: Measurement and Scientific Progress (2004).
18 If this statement seems strange, I refer the reader back to the discussion of the concept of the “gene.” To summarize, the theory of genes provides a highly accurate basis for predicting the heritability of traits, with actual hands-on applications, e.g., in the breeding of animals. But, modern biology strongly suggests that there is no such thing as a “gene,” at least not in the sense that the theory was traditionally understood.
19 Of course, a characteristic of light, which we discuss below, is that it appears to travel at the same speed whether approaching the front or the back of a moving body, that is, that its speed relative to a body is independent of the speed or direction of the motion of the observing body, contrary to “normal” experience. Thus, light as particles do not display the characteristics that Feynman says would be expected of his imagined gravity-inducing particles.
20 Einstein’s theory included the distortion of time as well as space, so that gravity also operates through the warping of time, which is a concept harder to visualize than the warping of space. Id., p.15n.
21 There is a gap between intuition and our pure sensory perceptions. Take the airplane. Our common sensory experiences probably tell us that the airplane flies because the force of the air on the underside of the moving wing pushes the airplane upwards. The aeronautical engineers tell us that, instead, the movement of the wing through the air creates a vacuum on the top of the wings which pulls the airplane upwards. The result is the same. The explanatory model is different. I think that our reasoning abilities allow us to incorporate the engineers’ model into our intuitive experience, even if our initial physical sensation would have suggested to us that the first model was correct. When you stick your arm out of the window of a moving car, you probably would say that you feel the air pushing your arm upwards and backwards. But, if you ask yourself is it possible that, in fact, a vacuum is pulling your arm upwards and backwards, you can conclude that the sensation is consistent with either explanation.
22 Lord Rees says that Einstein transcended Newton by offering insights into gravity that made it seem more “‘natural’ and linked it to the nature of space and time, and the Universe itself.” From Here to Infinity, p.81. I, like many (I would think), find the hypothesized curvature of space-time to be a concept that is far from normal. However, what Lord Rees probably means by “natural” is that the theory presents gravity as an integral part of the natural order, even if we find that natural order to seem contrary to the experiences of our sense or to our common sense.
23 More precisely, these criteria are not strictly requirements for achieving the status of a scientific theory but are standards for preferring one theory over another. Clearly, a useful theory will have the quality of generality, that is, it can extend to a wide variety of observations and consequences. In addition, philosophers of science and many scientists themselves consider simplicity to be not just a virtue but an inherent quality of a good theory. Simplicity may be hard to define and it would certainly seem to have some cultural basis (or bias), but it seems that it is often possible when confronted with two alternative theories, to identify the one that is more simple. Finally, there is elegance: “closely allied to simplicity, this regulative maxim separates what is ugly and cumbersome from sweeping ideas that carry élan and give pleasure upon comprehension.” Henry Morgenau, “What is a Theory?,” in Sherman R. Krupp (ed.), The Structure of Economic Science (1966), p.26. Elegance is undoubtedly a culturally-influenced criterion—certainly, what it is that constitutes elegance will be culturally determined; perhaps the relevance of the criterion itself is also a cultural phenomenon.
24 It can be argued that a history of successful predictions, especially predictions of things not already known, justifies a belief in the theory, at least until a better one comes along. This approach to science was formalized as the hypothetico-deductive model by Carl Hempel