Posts Tagged ‘inductive reasoning’

For Charles Darwin, natural selection was the key natural law driving evolution, as reflected in the title, On the Origin of Species, by Means of Natural Selection. Natural selection was envisioned as the mechanism for the origin of species—evolution.

Darwin declared – “I do believe that natural selection will generally act very slowly, only over long periods of time…. natural selection acts slowly by accumulating slight, successive, favorable variations.” In essence, natural selection was simply founded on a belief.

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Contrary to popular opinion, The Origin of Species was not a scientific work, and Charles Darwin makes that point very clear –

I am quite conscious that my speculations run quite beyond the bounds of true science.

Rather, Darwin called The Origin of Species “one long argument”—not a scientific showcase. Darwin makes this point because he knew what differentiates science from logic.

More than 200 years before the publication of The Origin of Species, English scientist Francis Bacon formalized what is now known as the Scientific Method – the only proven method of scientific inquiry for discovering natural laws.

As a founding member of the Royal Society, Bacon was quoted by Darwin in the preamble of The Origin of Species. The Scientific Method had earlier been used by Copernicus and Galileo overturning the geocentric worldview, and later by Isaac Newton that lead to the discovery of the natural laws of motion and gravity. Continue Reading

To our question “Did Darwin use the Scientific Method or Aristotelian logic?”—the answer is Aristotelian logic, otherwise known as deductive reasoning. Darwin decidedly wrote -

“No other work of mine was begun is so deductive a spirit as this; for the whole theory was thought out on the west coast of S. America before I had seen a true coral reef.”

Darwin’s theory was “thought out”—even before Darwin had seen the evidence. This is Darwin’s “I Think” approach. Darwin was caught swinging on the pendulum between the scientific method and logic, a popular trend in certain nineteenth century circles. 

At the time, use of inductive reasoning was being challenged by the popular British philosopher – John Stuart Mill. Mill promoted the use of deductive reasoning over the scientific method. In ascribing to Aristotelian logic, Darwin argues –

“How odd it is that anyone should not see that all observations must be for or against some view if it is to be of any service!”

Darwin continues –

“In fact the a priori reasoning is so entirely satisfactory to me that if the facts won’t fit, why so much the worse for the facts, in my feeling.” 

Ironically, the facts were irrelevant to Darwin. The major problem with deductive reasoning is that the conclusions can be misleading, inconclusive, and even erroneous. Darwin even concedes in The Origin of Species –

“For I am well aware that scarcely a single point (evidence) is discussed in this volume on which facts cannot be adduced, often apparently leading to conclusions (hypothesis) directly opposite to those at which I have arrived.”

Darwin did not use the scientific method, a fact he acknowledged. Two years before the publication of The Origin of Species, in writing to a friend, Darwin succinctly states –

“I am quite conscious that my speculations run quite beyond the bounds of true science.”

Newton applied the scientifc method. Discovery of the natural laws of gravity and motion by Newton over the centuries have been steadfast and practical. By contrast, in abandoning the scientific method with speculations, Darwin developed a theory that continues to be widely contested.

Do you think Darwin would have developed a different theory using the scientific method?

Building on the success of Copernicus and Galileo, Englishman Francis Bacon established and popularized their inductive reasoning approach as the primary methodology for conducting scientific inquiry. The method of investigation became known as the “Baconian Method” – now more popularly known as the “Scientific Method.” Bacon wrote - 

“Men have sought to make a world from their own conception and to draw from their own minds all the material which they employed, but if, instead of doing so, they had consulted experience and observation, they would have the facts and not opinions to reason about, and might have ultimately arrived at the knowledge of the laws which govern the material world.”

Bacon differentiated between “concepts” drawn from the “mind” and the “facts” drawn from the “evidence.” Concepts drawn from the mind can be influenced by prior knowledge, preconceived ideas, and traditions. Inductive reasoning limits the influence of bias.

In dedication to the estabishment of inductive reasoning, Bacon established the British Royal Society. Later in the nineteenth century, emphasis on the importance of inductive reasoning was further championed by William Whewell, a contemporary of Charles Darwin. To align with inductive reasoning, Darwin opens The Origin of Species with quotations from both Whewell and Bacon.

The question is, then, what is the difference between inductive and deductive reasoning? The difference between the scientific method and Aristotelian logic centers on determining the primary and secondary factors – also known as independent and depenent factors, respectively. The primary factor is the independent variable and controls the secondary (dependent) variable.

With inductive reasoning, the evidence is the primary factor and the hypothesis is the secondary, or dependent, factor. This means that the evidence takes precedence over the hypothesis – rejecting the influence of the bias.

This is the Scientific Method and the only approach proven to discover the laws of nature. Expressed in another way, the evidence with inductive reasoning is a free agent, and hypothesis becomes a slave to the evidence. The evidence trumps subjectivity.   

Deductive reasoning takes the inverse approach and the evidence becomes a slave to the hypothesis. This is known as Aristotelian logic where subjectivity can trump the evidence. Bias can rule. These diffences can be illustrated in a table format.

Scientific Method and Aristotelian logic are antithetical methods of inquiry. The next question is – what approach did Darwin take?

In this series, we will explore the difference between philosophy and science and specifically how the Scientific Revolution developed from use of the scientific method and how Darwin was eventually aligned between these opposing approaches to discovering the laws of nature – starting with Copernicus.

 Copernicus, by taking careful measurements to gather evidence, demonstrated that the Earth was not the center of the universe – rather, the Earth revolves around the sun. What made the key elemental difference was - the evidence. The evidence contradicted Aristotelian logic that had even crept into the Roman Catholic Church. The Scientific Revolution developed in concert along with a larger movement known as the Age of Enlightenment. In part, the movement was seeking to overthrow the Roman Catholic Church, which by the sixteenth century had even embraced Aristotle’s geocentric worldview.

 Driven to understand the universe as an act of the Creator, Copernicus wrote -  

 “The mechanisms of the universe, wrought for us by a supremely good and orderly Creator… the system best and most orderly artist of all framed for our sake.”

 Copernicus died in 1543 almost immediately after publishing his findings in the epochal book entitled On the Revolutions of the Celestial Spheres.

 While Copernicus’ escaped Roman Catholic Church rule, Galileo after confirming Copernicus’ findings was found guilty of “heresy” by the Inquisition in 1632. Thereafter, Galileo spent the last 10 years of his life under house arrest.

 Isaac Newton, after studying the evidence later in the eighteenth century, verified Copernicus’ and Galileo’s findings by using the scientific method. Newton is also known for discovering the laws of motion and gravity. When scientists at Britain’s Royal Society were asked in 2005 about who had the greater effect on the history of science, Newton or Albert Einstein – the vote went to Newton.

 The question is – what made the Scientific Revolution a revolution? The answer is – the system of reasoning. Aristotle logic was based on deductive reasoning. The Scientific Revolution was based on inductive reasoning.

 We will be exploring these differences in this series of blogs. What do you think is the difference between inductive reasoning and deductive reasoning? Is the difference important?