Sunday, May 12, 2019

Neptune’s Discovery Shows How Proven Facts About Nature Are ‘Logically Necessary’ and Could Not Have Been Anything Else

Stuart K. Hayashi

Many educated people believe that there’s a distinction between observed facts (synthetic truths, arrived at through sensory observation and inductive reasoning) vs. logical necessities (analytic truths, arrived at through deductive reasoning). The latter refers to conclusions that are deduced and could not be anything other than what they are, such as “3 + 2 = 5.” Such educated people believe these two types of truths must be distinct because “theoretically, natural laws like gravity could have turned out different from what they are. For instance, it’s true that, when water freezes, the molecules move further from one another, but it’s theoretically possible that this principle could have turned out differently, with water freezing making the molecules go closer together.” But no, synthetic truths and analytic truths are the same: any natural phenomenon that isn’t directly subject to a conscious entity’s volition is something that couldn’t have natural properties different from what they are.

Image of Neptune from NASA JPL;
via Wikimedia Commons.
Example: in the late 1830s, scientists only observed the existence of seven planets in the solar system. However, John Couch Adams and Urbain Le Verrier — working separately from one another —noticed unusual behavior of Uranus in its orbit. Before directly observing such, Adams and Le Verrier each deduced that there had to be an eighth solar-system planet that would be located in a specific location in relation to Uranus. Such a planet being in a particular location in relation to Uranus would explain the anomolies of Uranus’s orbit. Later, based on Le Verrier’s work, Johann Gottfried Galle searched for the then-unknown planet in that location and found it: Neptune.

One might conclude that because Adams and Le Verrier deduced Neptune’s existence and location without first observing Neptune itself, this event undermines the credibility of inductive reasoning. The opposite is true: it affirms the validity of inductive reasoning.

According to the Law of Identity, insofar as you know the natural attributes of an entity, the easier it should be for you to predict that entity’s behavior in a specific situation. Insofar as you understand the nature of gravity and a tennis ball — an understanding you initially gained through sensory observations — you should be able to predict that in the next instance where you lift a tennis ball and release your grip on it, the tennis ball should fall to the ground. That is the source of the principle of “prediction-making” and “replicability” in science — if Scientific Party 1 claims to have observed, under specific conditions, that a stimulus of type A will consistently elicit the same specific response in an entity of type B, then it follows that that if Scientific Party 2 reproduces those pertinent conditions, its provision of a stimulus of type A should elicit the same response in an entity of type B.

Through observations of the first seven planets of the solar system, scientists induced their knowledge that the gravitational pull of other objects will act upon planets and their orbits in a specific fashion. Then, considering observations of Uranus’s behavior in orbit, John Couch Adams and Urbain Le Verrier applied the Law of Identity to deduce that in relation to Uranus there had to be another planet in a specific location that was affecting Uranus enough to cause the irregularities of its orbit. Then sensory observation by Galle proved Adams and Le Verrier to be correct.

It wasn’t the case Adams and Le Verrier were just lucky in guessing the location of an eighth planet from the sun. From a set of principles — principles originally induced through observation and inductive reasoning — Adams and Le Verrier deduced the logically-necessary conclusion that there was an eighth planet from the sun in a specific location in space in relation to Uranus. That was an analytic truth. Then this was proven through a more direct observation — a synthetic truth. There isn’t an unbridgeable distinction between analytic truth and synthetic truth — they are the same. If some natural phenomenon isn’t being manipulated by some volitional being (humans), then its existence and actions could not — in sound theory — be anything other than what they are: recognition of its existence and actions is “logically necessary.”

Here is another example of which I have previously written on Facebook: first, scientists observed a lot of data about prehistoric creatures that were in a “transitional” stage between fish and four-legged amphibian. This was information processed inductively. Then, based on such information, Neil Shubin and Ted Daeschler deduced that if there were any more remains of such fish-amphibian creatures to be found, they should be on Ellesmere Island near Canada. That was an analytic conclusion. Shubin and Daeschler went to Ellesmere Island and found this fossil, which they named Tiktaalik roseae. Its existence and properties were a synthetic truth.

Principles of Nature that you observe (synthetic truths) are, through the Law of Identity, consistently applicable insofar as they are understood , and thus logically necessary (analytic truths). Accordingly, to contradict such an observed fact and synthetic truth as the existence of Neptune or Tiktaalik is also to contradict deductive logic, as contradicting this fact commensurately contradicts the deductive reasoning and prior known facts that Le Verrier and Shubin respectively undertook to arrive at conclusions that were later empirically proven.