Tagged: logic

The Elements of Reasoning

elements of reasoning conway munson 2nd edition wadsworth 1997The Elements of Reasoning by David A. Conway and Ronald Munson, 2/5

This book provides an introduction to informal logic, focusing mostly on valid and invalid ways arguments can be formed, along with a brief look at common fallacies and errors in reasoning.  The argument forms seem contrived and the analysis methods limited–it is hard to imagine a use for these concepts outside of a classroom and the book is certainly not written in a way meant to smooth the transition from academic thought exercise to real life.  In fact, the whole tone of the book is very dry and dead, which is a pity because the topic is fascinating and I have seen it treated in much more interesting and lively ways.  A good teacher could bring it to life, perhaps, and also provide insight on the numerous thought exercises that the authors leave unanswered.

Why I read it: I wanted to learn about the symbols used in formal logic (only a few of which are covered in this book) and the title caught my eye at the thrift store.


Historians’ Fallacies

historians fallacies hackett fischer harper perennial 1970Historians’ Fallacies: Toward a Logic of Historical Thought by David Hackett Fischer, 5/5

Fallacies everywhere!  Browsing through eleven categories of faulty reasoning, all illustrated by examples from published works of historical scholarship, made me feel like a kid in a candy shop.  My initial reservation–that it isn’t very respectable to do nothing but pick apart the works of one’s colleagues–was satisfactorily addressed in Fischer’s deliciously cogent introduction to the book.  Here, the author acknowledges the dual impossibility and necessity of defining a logical approach to the study of history and justifies his negative method with the respectable goal “to extract from these mistakes [in other historians’ reasoning] a few rough rules of procedure” (xviii).

Though some may find his approach off-puttingly critical, the author is no intellectual slouch–many of the fallacies he addresses are so subtle that I am impressed he could identify them at all, much less find relevant examples in the wild.  Though the topic is very specific, the application is broad–historians aren’t the only ones who are susceptible to fallacies of question-framing, factual verification, factual significance, generalization, narration, causation, motivation, composition, analogy, semantical distortion and substantive distraction.

Why I read it: The title caught my eye as I was browsing through Easton’s Books.  The owner was so surprised that someone was actually interested in the book (he’d almost thrown it out, thinking no one would ever buy it) that he gave me a discount and said I’d made his day.

A picture quote I made:


LogicLogic: or, the Right Use of Reason in the Inquiry After Truth with a Variety of Rules to Guard Against Error in the Affairs of Religion and Human Life, as well as in the Sciences by Isaac Watts, D.D., 4/5

Watts’ optimistic attempt to break down and methodise the ideal workings of the human brain is a little too prosaic to leave much of an impression and a little too complicated to be easily applicable to everyday life.  However, the text is accessible, unpretentious and impeccably organised, addressing in four parts the topics of perception and ideas,  judgment and proposition, reason and syllogism, disposition and method.  Watts provides common-sense categorisations of all beings (divided into possible or actual, substance or mode, simple or compound, animate or inanimate, etc.), ideas (sensible, spiritual or abstracted, simple or complex, compound or collective, universal or particular, etc.), words (negative or positive, simple or complex, common or proper, etc.), propositions (universal, particular, indefinite or singular, affirmative or negative, etc), prejudices (arising from things, words, ourselves or other persons), syllogisms (universal or particular, negative or affirmative, simple, complex, conjunctive or compound, etc.) and methods (natural or arbitrary, synthetic or analytic).

The only part that went almost completely over my head was that on syllogisms, where I would have appreciated a clearer definition of terms and perhaps some diagrams.  My favourite sections were not those in which Watts laid out the reasonably obvious in painstaking detail, but rather the parts where he spoke wisely about human nature and tendencies.  I never tire of rediscovering that people are just people, no matter how far back in the past they existed.

Two parts that I found particularly insightful and affecting were those on overly-emotional people and sceptics.  On the first topic, Watts kindly advises that “this sort of people ought to judge of things and persons in their most sedate, peaceful, and composed hours of life, and reserve these judgments for their conduct at more unhappy seasons” (204).  About scepticism (a fault towards which I tend), Watts explains:

Scepticism is a contrary prejudice.  The dogmatist is sure of every thing, and the sceptic believes nothing.  Perhaps he has found himself often mistaken in matters of which he thought himself well assured in his younger days, and therefore he is afraid to give assent to anything again.  He sees so much show of reason for every opinion, and so many objections arising also against every doctrine, that he is ready to throw off the belief of every thing; he renounces at once the pursuit of truth, and contents himself to say, There is nothing certain.  It is well if, through the influence of such a temper, he does not cast away his religion as well as his philosophy, and abandon himself to a profane course of life, regardless of hell or heaven.

Both these prejudices last mentioned [dogmatism and scepticism], though they are so opposite to each other, yet they arise from the same spring, and that is, impatience of study, and want of diligent attention in the search of truth.  The dogmatist is in haste to believe something; he cannot keep himself long enough in suspense, till some bright and convincing evidence appear on one side, but throws himself casually into the sentiments of one party or another, and then he will hear no argument to the contrary.  The sceptic will not take pains to search things to the bottom, but when he sees difficulties on both sides, resolves to believe neither of them.  Humility of soul, patience in study, diligence in inquiry, with an honest zeal for truth would go a great way towards the cure of both these follies” (202).

[Why I read it: a PDF version (from my dad, I think) sat in my Downloads folder for years, but I never read it because I hate reading books on the computer.  I was about to delete the file, when I decided it still looked pretty interesting and ordered a proper copy from the library through inter-library loan.]