"A CASE OF SIMPLE DEDUCTION, WATSON!"

Or was it?

Classic induction proceeds “at once from . . . sense and particulars up to the most general propositions." Francis Bacon


I believe Sherlock Holmes (if Conan Doyle ever really had him state that response to Watson) was wrong. Holmes characteristically made observations and formulated conclusions from those specific experiences and thus probably did not use deductive reasoning (deduction) to arrive at his conclusions--but rather induction.

Tonight, (May 18th 2010) I listened to a program on MSNBC in which the journalist Jonathan Alter, spoke about his new book concerning President Obama's first year. Alter stated that he had interviewed over 200 people for the book which is entitled "The First Year". In response to a question by Joe Scarborough (whom I paraphrase here): "How does the President really 'think', and is he really so abrupt--perhaps sharp tongued-- with his staff as some say?" asked Scarborough. Alter responded that the President was "self confident" and agreed that the President probably most often sees himself as the "smartest guy in the room". As to his reasoning power, Alter stated that Obama tends to think "inductively" while, in comparison, former President Clinton was likely to be more "deductive" of a thinker. What did he mean?

We often get these concepts--induction and deduction confused.
But I suspect Alter was probably correct in his general characterization. Obama is more rational and methodological and Clinton was more emotional--more likely to have a gut rather than a cerebral response. But is that what inductive and deductive actually mean? Let's see.

Aristotle was actually the first to give us the word induction and deduction. His philosophical premise that all knowledge came from sensory experience required a set of terms to explain his process. The concept of empiricism (from the Greek word "ἐμπειρία" (empiria) translates as: "experience". In epistemology (the study of how we "know") empiricism is the theory that states that knowledge arises from our senses. Aristotle(as opposed to his near contemporary, Plato, who espoused the concept of "innate ideas" divorced from experience)emphasized the role of experience and physical observational evidence, especially sensory evidence in the formation of ideas. A fundamental tenet is that a priori knowledge (knowledge independent of experience) such as intuition,dreams,revelation, imaginings are by definition excluded from consideration. Modern science is thus strictly empirical in nature.

Aristotle also was the first to use the term "induction" which in Greek is επαγωγή(epagogi) which translates as variously as "inductance", "induction", or "inference", but it is unlikely that he used it in its present meaning, since he differentiated between "epagogi" or inferential thought and "reasoning" which he termed "σνλλογισμÒς"(syllogismos). Thus, Aristotle considered inductive reasoning only as a preliminary process, a means of moving mentally from some particular concept to universal statements which then could be inserted into a rational thought process or actual human reasoning which he had distilled into the well known syllogistic form from which actual conclusions could be derived. If you accept the premise (below) the conclusion follows necessarily. This Aristotle considered "reasoning".

Such as this syllogism (an example of deductive reasoning):

All Republicans are biased meatheads,
Ralph is a Republican,
Therefore: Ralph is a biased meathead.

A general statement to a specific conclusion. The end product is a logical progression but is it valid? Ahh that is another question all together.

In the Middle Ages, Aristotle's concepts were worked over and modified by others.
There were also significant developments in the Middle East by Arab scholars.

In Europe, Roger Bacon 1214-1294 was a Franciscan monk,philosopher,writer, and scientist who was born in Ilchester, Somersetshire,about 1214 and died at Oxford, perhaps on 11 June, 1294. Bacon joined the Franciscan Order in 1256.

Roger Bacon elaborated on Aristotle's empiricism and use of induction and deduction. He used a method of investigation which he described as a repeating cycle of observation, hypothesis, experimentation, and independent verification. He recorded the way he had conducted his experiments in precise detail, perhaps with the idea that others could reproduce and independently test his results. Pope Clement IV (1265) granted Bacon (who was under a general proscription to write for publication) a specific commission to advise him on scientific matters. Within two years Bacon has written three major works(Opus Major, Minor and Tertium)and submitted them to the Pope. In these treatises Bacon discusses the four causes of error: "authority, custom, bias opinion of the unschooled, pretense of knowledge."

InductionBacon also evaluates the four causes of error: "authority, custom, the opinion of the unskilled many, and the concealment of real ignorance by a pretense of knowledge". He distinguishes between speculation and experimental science. Science he states, verifies its conclusions by direct experiment, and thus has the potential to open knowledge of the past and future.

So what we may conclude is that both inductive and deductive reasoning are essential in logical thinking. Inductive reasoning is based on specific observations which can lead to general statements. These generalities (after exhaustive testing) may lead to general rules or laws. Other statements may then be confidently "deduced" from these general laws to specific examples by deductive reasoning.

Inductive reasoning --gathering observations or experience--and generalizing from those experiences are very natural to humans and certainly must have contributed to our ascendancy over unthinking beasts in prehistoric times.

So yes Holmes used inductive reasoning not deductive reasoning.

If as Alter states, Obama tends to think "inductively" (i.e. from specific observations to general) while, in comparison, former President Clinton was likely to be more "deductive" of a thinker (i.e. from general principles or laws to specific details) Was he correct? I think not. More likely he like many of us simply confused the two terms. My impression is that Obama is the more deductive thinker...beginning with general principles and arriving methodically by following an almost syllogistic structure at answers to specific conclusion. While Clinton was the more inductive thinker..beginning with specific observations and experiences and arriving at general conclusions. Who is better....we need them both.