Section 3–1 Introduction

(Natural philosophy / Relation to other sciences / Love)

In this chapter, Feynman states that he would explain the fundamental problems in the other sciences and “how they get along with physics.” However, it is impossible to deal with the complex, subtle, beautiful matters in these other fields in “so small a space.” In this section, the three interesting points mentioned are natural philosophy, relation to other sciences, and love.

(If you listen to the CD of this Feynman’s lecture, he mentions that it is impossible to explain the fundamental problems in the other sciences within “45 minutes.”)

1. Natural philosophy:

“… physics is the present-day equivalent of what used to be called natural philosophy, from which most of our modern sciences arose (Feynman et al., 1963, section 3.1 Introduction).”

Philosophers may not completely agree with Feynman that physics is equivalent to natural philosophy from which most of the modern sciences arose. In Dictionary of Concepts in the Philosophy of Sciences, there are two definitions of natural philosophy: “1. The name for science until well into the nineteen century. 2. The philosophy study of nature, parallel or complementary to both science and the philosophy of science; this usage is older than modern science but persists in certain philosophical circles (Durbin, 1988, p. 201).” Historically speaking, Newton (1687) formulates three laws of motion in Principia: Mathematical Principles of Natural Philosophy. In the conclusion to the Principia, he writes that, “[a]nd thus much concerning God, to discourse of whom from the appearance of things, does certainly belong to Natural Philosophy (Newton, 1687, p. 442).” In other words, Newton’s notion of natural philosophy includes a role of God in physical phenomena.

Note: As another example, Treatise on Natural Philosophy (Thomson & Tait, 1867) is a physics textbook written by Lord Kelvin and Peter Guthrie Tait. In addition, Truesdell (1966) published a book titled, Six Lectures on Modern Natural Philosophy and tried to revive the term Natural Philosophy.

2. Relation to other sciences:

“… Lack of space also prevents our discussing the relation of physics to engineering, industry, society, and war, or even the most remarkable relationship between mathematics and physics (Feynman et al., 1963, section 3.1 Introduction).”

According to Feynman, it is not possible to discuss the relation of physics to engineering, industry, society, war, and even mathematics within 45 minutes in this lecture. He explains that mathematics is not a natural science because the test of its validity is not experiment. Nevertheless, experimental mathematics is a branch of mathematics in which computation is used to investigate mathematical structures and identify their fundamental properties and patterns. Simply phrased, experimental mathematics has been used to make mathematical predictions such that they can be verified by using computational experiments. Importantly, Feynman path integrals can be applied in financial modeling, and thus, it is also worthwhile nowadays to discuss the relation of physics to finance.

Note: If you listen to the CD of this Feynman’s lecture, he mentions that mathematics is perhaps an unnatural science.

3. Love:

“… We must, incidentally, make it clear from the beginning that if a thing is not a science, it is not necessarily bad. For example, love is not a science. (Feynman et al., 1963, section 3.1 Introduction).”

Feynman says that love is not a science, however, there are studies on the science of love. The feeling of love could be analyzed from the perspective of chemical reactions because human beings are essentially “human molecules.” For instance, there are experiments on hormonal changes of human beings that were falling in love (Marazziti & Canale, 2004). The symptoms of love such as sweaty palms, shaky knees, are sometimes explained to be due to a chemical, “phenylethylamine,” which has been named as the “love molecule.” Although Feynman explains earlier that human molecules and everything can be reduced to atoms, he would possibly argue that our knowledge of love molecules, as well as dopamine, and norepinephrine, are still incomplete.

Four years after delivering this lecture, Feynman (1965) suggests that “[i]f it were possible to state exactly, ahead of time, how much love is not enough, and how much love is over-indulgent, then there would be a perfectly legitimate theory against which you could make tests (p. 159).” Simply phrased, it is difficult to precisely quantify the amount of love.

Note: Interested students should read Liebowitz’s (1983) The Chemistry of Love.

Questions for discussion:

1. How is physics equivalent to natural philosophy?

2. Is mathematics an unnatural science?

3. Can love be explained by science?

The moral of the lesson: students of many other fields find themselves studying physics because of the basic role it plays in all phenomena.

References:

1. Durbin, P. T. (1988). Dictionary of Concepts in the Philosophy of Sciences. Westport: Greenwood.

2. Feynman, R. P. (1965). The character of physical law. Cambridge: MIT Press.

3. Feynman, R. P., Leighton, R. B., & Sands, M. (1963). The Feynman Lectures on Physics, Vol I: Mainly mechanics, radiation, and heat. Reading, MA: Addison-Wesley.

4. Liebowitz, M., R. (1983). The Chemistry of Love. Boston: Little, Brown, & Co.

5. Marazziti, D., & Canale, D. (2004). Hormonal changes when falling in love. Psychoneuroendocrinology, 29(7), 931-936.

6. Newton, I. (1687/1995). The Principia (translated by A. Motte). New York: Prometheus.

7. Thomson, W., & Tait, P. G. (1867). Treatise on Natural Philosophy. Oxford: Oxford University Press.

8. Truesdell, C. (1966). Six Lectures on Modern Natural Philosophy. Springer-Verlag.