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Types of logic

In a very useful paper Jayanti (2011) compares deductive, inductive and abductive logic.  I am using her examples here because they are couched in business language and are easier to remember than the examples used in textbooks.

I also would like to extend Jayanti’s typology to conductive logic described by Floridi (2017).

Floridi, L. (2017). The Logic of Design as a Conceptual Logic of Information. Minds and Machines, 1–25. https://doi.org/10.1007/s11023-017-9438-1

Jayanti, E. B. (2011). Toward Pragmatic Criteria for Evaluating HRD Research. Human Resource Development Review, 10(4), 431–450. https://doi.org/10.1177/1534484311412723

Deductive reasoning

All companies have logos.

This organisation is a company.

Therefore, it has a logo.

We assert truths about the world (All companies have logos) and about the case (the organisation is a company).  If the assertion about the case is true (usually justified in the Participants section), then whether or not it has a logo ‘tests’ the truth of the first statement.

When we only want to test the idea that more companies than none have a logo, then we can take a sample of companies. If they have more logos than we can contribute to measurement error, we accept that the first statement is not wrong.

Induction

All these organisations are companies.

All these organisations have logos.

Therefore, all companies have logos.

This methodology begins with data-in-hand and constructs a rule that is similar to the truth asserted in the first example.  In the first example, we intend to test the statement.  In this example, we arrive at the statement and we could go on to test it as before.

We can see the ‘stretch’ in inductive reasoningand most of us are uncomfortable unless this is exploratory research and the work moves on to that test.

This logic may also be useful for accounting for a case, in which case the truth value of the assertion is a methodological question that remains within the case and is not generalized beyond the case.

We are asserting information about the conclusion rather than the starting premise but in most ways it is used, this is simply a version of the positivistic paradigm as the example under deduction

Abduction

All companies have logos.

This organisation has a logo.

Therefore, this organisation is probably a company.

The ‘stretch’ here is even greater than under induction, but it is limited to the case-in-hand.  It is when what we assumed would be true about case is evidently not so that we put a question mark around the first statement.

The purpose of abductive reasoning is to be practical. We are trying to make sense of one case and extend things we ‘know/believe’ to be true.  Surprise requires us to take action and think again.  We accept plausible, coherent accounts until they do not work.

Conduction

Floridi (2017) suggests conduction goes further than abduction.  Writing as an information theorist, a technologist takes a set of requirements and puts together a system that satisfies those requirements. The movement from requirements to the system is conduction.  The system can still be tested deductively (does it meet the requirements?).

How could be phrased this in terms of companies and logos?

I want this to be company, meaning, it needs a legal persona of its own and must be recognised as an entity separate from its owners and have limited liability. These are requirements.  The organisation must be able to do {a, b, c}.

And the working solution could be {name, logo, registration and founding documents, directors to act for it, an official address to serve legal papers, an initial capital investment, up-to-date accounts}.  The organisation will have {x, y, z}.

We may work this out mimetically, and probably do. Imagining, the solution is conduction and has to be constructed in the local situation  . . . that is situated and embodied.

The imaginative solution also depends upon past experience, i.e.,  knowing what will work together and what the actor is able to do.

The imaginative solution anticipates meeting the requirements but it is likely that there many, but not any sets of requirements that would suffice.

 

Published in Logic

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