Straight and Crooked Thinking

 

Straight and Crooked Thinking (first published in 1930, with revisions in 1953 and 1974) by Robert H. Thouless is a classic, practical guide to clear reasoning and detecting flawed or deceptive argumentation. Written for the general reader (“the man in the street”), it focuses on everyday discussions of controversial or political topics rather than formal academic logic. Thouless, a psychologist, emphasizes how emotions, language ambiguities, and dishonest tactics distort thinking, and how to counteract them with rational analysis.

The Core Processes of Thought: Straight vs. Crooked Thinking

•  Straight thinking is clear, logical, rational, evidence-based, and free from distortion. It relies on accurate language, valid inferences, consideration of evidence, and avoidance of emotional bias or fallacies. It aims at reaching conclusions that align with facts and sound reasoning.

•  Crooked thinking involves distortions—intentional or unintentional—that twist arguments away from truth. These arise from emotional influences, sloppy language, logical errors, or deliberate tricks to persuade without solid grounds.

The book teaches a system for analyzing whether others (or oneself) are using straight or crooked thinking by systematically checking arguments against common sources of error.

How to Identify Crooked Thinking (Key Detection Methods)

Thouless provides practical tools to spot flaws:

1.  Examine emotional language and meanings — Words often carry strong emotional connotations (e.g., “freedom” vs. “licence”, or loaded terms like “Bolshevik” or “reactionary” in his era). Identify when emotive words replace factual description to sway feelings rather than reason.

2.  Check quantifiers: “All” vs. “Some” — A major source of crooked thinking is overgeneralization. Statements true only for “some” cases are presented as if they apply to “all” (or vice versa). Test by asking: Does this hold for every instance, or just some? Insert “all” or “some” explicitly to expose the flaw.

3.  Spot dishonest tricks in argument — Thouless lists many tactics like:

•  Shifting ground (changing the proposition mid-argument).

•  Misrepresenting the opponent’s position (straw man).

•  Appealing to irrelevant authority.

•  Using emotionally charged anecdotes instead of evidence.

•  Circular reasoning.

4.  Detect logical fallacies — Common ones include false cause (post hoc ergo propter hoc), false dilemma (only two extremes), affirming the consequent, etc. The book explains these in plain terms with examples.

5.  Analyze language precision — Words and facts must match. Vague, ambiguous, or shifting definitions allow crooked thinking to hide.

6.  Evaluate evidence and probability — Crooked thinking often ignores degrees of certainty, overstates probabilities, or dismisses evidence selectively.

To apply this: When hearing an argument, pause and ask:

•  What exactly is being claimed?

•  Is the language clear and neutral, or emotionally loaded?

•  Are generalizations overextended?

•  Are any of the 37 dishonest tricks (listed in an appendix in some editions) present?

•  Does the reasoning follow logically without fallacies?

•  Is evidence properly used?

This systematic scrutiny reveals whether the thinking is straight (logical and honest) or crooked (distorted, evasive, or manipulative).

The System of Logic in the Book

Thouless does not present a formal deductive system (like Aristotelian syllogisms or symbolic logic). Instead, it offers a practical, informal logic tailored to real-world debates:

•  Emphasis on clear definition and precise language to avoid equivocation.

•  Focus on valid inference — ensuring conclusions follow from premises.

•  Vigilance against emotional and rhetorical distortions (which psychology shows affect judgment).

•  Tools for critically evaluating everyday arguments rather than abstract proofs.

•  Promotion of detached, evidence-based reasoning over passion-driven or dogmatic positions.

It’s more a “hygiene of thought” — rules for clear thinking and fallacy-spotting — than a rigorous philosophical logic textbook.

What Else Is the Book About?

Beyond fallacies and argument analysis, it covers:

•  The role of emotion in twisting thought (how feelings bias perception and argument).

•  Prejudice and how it leads to crooked thinking on both sides of divides (e.g., political left/right examples from the time).

•  Propaganda techniques and how language is weaponized in controversy.

•  The importance of intellectual honesty — recognizing one’s own crooked thinking.

•  Probability and scientific thinking — handling uncertainty rationally (avoiding over-certainty or false precision).

•  The future of straight thinking — optimism that better awareness can improve public discourse.

The book includes many real-world examples from politics, religion, and social debates of the era (updated in revisions), plus an appendix listing 37 dishonest tricks commonly used in argument, with countermeasures.

Overall, it’s a timeless manual for clearer thinking, resisting manipulation, and arguing more effectively and honestly. Many consider it an early precursor to modern critical thinking texts.