Logic And Critical Thinking In Medicine

"Critical thinking is a desire to seek, patience to doubt, fondness to meditate, slowness to assert, readiness to consider, carefulness to dispose and set in order; and hatred for every kind of imposture." - Francis Bacon (1605)

As parents, we are tasked with instilling a plethora of different values into our children. While some parents in the world choose to instill a lack of values in their kids, those of us that don't want our children growing up to be criminals and various misfits try a bit harder. Values and morality are one piece of the pie. These are important things to mold into a child's mind, but there are also other items in life to focus on as well. It starts with looking both ways to cross the street and either progresses from there, or stops.

If you stopped explaining the world to your children after they learned to cross the street, then perhaps you should stop reading and go back to surfing for funny pictures of cats. I may use some larger words that you might not understand, making you angry and causing you to leave troll-like comments full of bad grammar and moronic thought processes. However, if you looked at the crossing the street issue as I did – as a logical problem with cause and effect and a probable solution – then carry on. You are my target audience.

Or perhaps the opposite is true, as the former are the people that could benefit from letting some critical thinking into their lives. So what exactly is critical thinking? This bit by Linda Elder in a paper on CriticalThinking.org pretty much sums it up:

Through critical thinking, as I understand it, we acquire a means of assessing and upgrading our ability to judge well. It enables us to go into virtually any situation and to figure out the logic of whatever is happening in that situation. It provides a way for us to learn from new experiences through the process of continual self-assessment. Critical thinking, then, enables us to form sound beliefs and judgments, and in doing so, provides us with a basis for a 'rational and reasonable' emotional life. — Inquiry: Critical Thinking Across the Disciplines, Winter, 1996. Vol. XVI, No. 2.

The rationality of the world is what is at risk. Too many people are taken advantage of because of their lack of critical thinking, logic and deductive reasoning. These same people are raising children without these same skills, creating a whole new generation of clueless people.

To wit, a personal tale of deductive reasoning:

Recently I needed a new transmission for the family van. The warranty on the power train covers the transmission up to 100,000 miles. The van has around 68,000 miles on it. Therefore, even the logic-less dimwit could easily figure that the transmission was covered. Well, this was true until the dealership told me that it wasn't, stating that because we didn't get the scheduled transmission service (which is basically a fluid change) at 30,000 and 60,000 miles the warranty was no longer valid. Now, there are many people that would argue this point, but many more that would shrug, panic, and accept the full cost of repairs.

I read the warranty book. I had a receipt that said the fluid was checked at 60,000 but not replaced. A friend on Twitter pointed out the fact that they were using 100,000 mile transmission fluid. So logically, the fluid would not have to be replaced under 100,000 miles if it wasn't needed, right? So why the stipulation that it needed to be replaced at 60,000 and the loose assumption that not doing that would void the warranty? So I asked the warranty guy to show me in the book where the two items are related. Where it explicitly says that if you don't get the service, the transmission isn't covered. There were portions where it said the service was recommended, but never connecting to actual repairs. Finally the warranty guy shrugged, admitted I was right and said the service was covered.

In this case, valid logic equaled truth and a sound argument. I used very simple reasoning and logic to determine that I was being inadvertently screwed. I say "inadvertently" because I truly believe based on their behavior that they were not intentionally trying to screw me. They believed the two items were related, they had had this argument many times before and were not prepared to be questioned. While both the service manager and the warranty guy seemed at least junior college educated, proving my argument to them took longer than it should have between three adults.

However, valid logic does not always guarantee truth or a sound argument. This is where it gets a little funky. Valid logic is when the structure of logic is correct in the way of syntax and semantics rather than truth. Truth comes from deductive reasoning of said logic. For example:

All transmissions are covered parts. All covered parts are free. Therefore, all transmissions are free. This logic is technically valid, and if the premises are true, then of course the conclusion must be true. You can see here however that it's not always true, though in some situations it could be. While the logic is valid, not all transmissions are free, only those covered by the warranty. So based on that, saying all transmissions are free is not sound logic.

To take it one step further:

All Daleks are brown. Some brown things are Cylons. Therefore, some Daleks are Cylons. Sci-fi fan or not, you probably know that this is not true. The basic lesson here is that, while the logic above might seem valid because of the structure of the statement, it takes a further understanding to figure out why it's not necessarily true: That is, based on the first two statements it's possible that some Daleks are Cylons, but it's not logically concludable. That's where deductive reasoning comes on top of the logic. The underlying lesson here is not to immediately assume everything you read or are told is true, something all children need to and should learn.

This is the direct lesson that needs to be passed on to our children: that of not accepting the immediately visible logic. While not all problems are complex enough to require the scientific method, some of them need some deduction to determine if they are true. Take the example above — how many kids would immediately be satisfied with the false conclusion? Sure, it's a bit geeky with the examples, but switch out bears for Daleks and puppies for Cylons. That makes it easier, and takes the actual research out of it (to find out what Daleks and Cylons are respectively) but many people would just accept that in fact some bears are puppies, if presented with this problem in the context of a textbook or word problem.

Maybe I'm being paranoid or thinking too doomsday, whatever, but I think this is an epidemic. Children are becoming lazier and not as self sufficient because their parents have a problem with watching a three year old cry after they tell her to remove her own jeans, or ask her to put away her own toys (yes, organizational logic falls under the main topic). These are the same parents who do their kid's science project while the kid is playing video games. These kids grow up lacking the simple problem solving skills that make navigating life much easier. Remember when you were growing up and you had the plastic stacking toys? Well, instead of toys for early development like that, parents are just plopping their kids down in front of the television. While there is some educational type programming on television, it's just not the same as hands-on experience.

My father is an engineer, and he taught me logic and reasoning by making me solve simple, then complex, problems on my own. Or at least giving me the opportunity to solve them on my own. This helped develop critical thinking and problem solving skills, something a lot of children lack these days. Too often I see children that are not allowed to solve problems on their own; instead their parents simply do it for them without argument or discussion. Hell, I am surrounded by adults every day that are unable to solve simple problems, instead choosing to immediately ask me at which point I have to fill the role that their parents never did and – knowing the solution – tell them to solve it themselves, or at least try first.

One of the things I like to work on with my kids is math. There is nothing that teaches deductive reasoning and logic better than math word problems. They are at the age where basic algebra can come into play, which sharpens their reasoning skills because they start to view real world issues with algebraic solutions. Another thing is logic puzzles, crossword puzzles and first person shooters. Actually, not that last one. That's just the reward.

Since I weeded out the folks that don't teach their kids logic in the first two paragraphs, as representatives of the real world it's up to the rest of us to spread the knowledge. It won't be easy. The best thing we can do is teach these thought processes to our children, so that they may look at other children with looks of bewilderment when other children are unable to solve simple tasks. Hopefully, they will not simply do the task for them, but teach them to think. I'm not saying we need to build a whole new generation of project managers and analysts, but it would be better than a generation of task-oriented mindless office drones with untied shoelaces, shoving on a door at the Midvale School for the Gifted.

h/t to @aubreygirl22 for the logical conversation.
Image: Flickr user William Notowidagdo. Used under Creative Commons License.

1. Sackett DL, Rosenberg WMC, Muir Gray JA, et al. Evidence based medicine: what it is and what it isn’t. BMJ. 1996;312:71–72.[PMC free article][PubMed]

2. Straus SE, Scott Richardson W, Glasziou P, Haynes RB. How to Practice and Teach EBM. 3rd Edition. Edinburgh, London, New York, Toronto: Elsevier/Churchill Livingstone; 2005. Evidence-Based Medicine.

3. Finocchiaro MA. Two empirical approaches to the study of reasoning. Informal Logic. 1994;16:1–21. (See also reprint, pp. 65–91 in: Finocchiaro MA. Arguments about Arguments. New York and Cambridge: Cambridge University Press, 2005)

4. Groopman J. How Doctors Think. New York: Houghton Mifflin Company; 2007.

5. De Bono E. A Textbook of Creativity. London: Penguin Books; 1990. Lateral Thinking. (current printing; first published by Ward Lock education, 1970)

6. Dewey J. How We Think. Boston: D.C Heath; Mineola, NY: Dover Publications; 1997. 1910.

7. Ennis RH. Critical thinking: A streamlined conception. Teaching Philosophy. 1991;14(1):5–25.

8. The Critical Thinking Community. Defining Critical Thinking. A statement by Michael Scriven & Richard Paul for the National Council for Excellence in Critical Thinking Instruction. 2 pages at http://www.criticalthinking.org/aboutCT/definingCT.cfm, retrieved March 12, 2010.

9. Facione PA. Research findings and recommendations prepared for the Committee on Pre-College Philosophy of the American Philosophical Association. 1990. Critical Thinking: A Statement of Expert Consensus for Purposes of Educational Assessment and Instruction; pp. 315–423. ERIC Document # ED.

10. Fowler B. Critical Thinking across the Curriculum Project. Critical thinking definitions. 5 pages at http://mcck.edu/longview/ctac/definitions.htm, retrieved Oct 24, 2007.

11. AUSTHINK. Definitions (of Critical Thinking) 4 pages at < http://www.austhink.org/critical/pages/definitions.html, retrieved Oct 24, 2007.

12. Ennis RH. A taxonomy of critical thinking dispositions and abilities. In: Baron JB, Steinberg RJ, editors. Teaching Thinking Skills: Theory and Practice. New York: WH Freeman; 1987. pp. 9–26.

13. Ennis RH. A concept of critical thinking: a proposed basis for research in the teaching and evaluation of critical thinking ability. Harvard Educational Review. 1962;32:81–111.

14. Ennis RH, Millman J, Tomko TN. Cornell Critical Thinking Tests Level X & Level Z. Third Edition. Pacific Grove, CA: Midwest Publications; 1985.

15. Ennis RH, Weir E. The Ennis-Weir Critical Thinking Essay Test. Pacific Grove, CA: Midwest Publications; 1985.

16. Facione PA. California Critical Thinking Skills Test, Forms A and B. Millbrae, CA: California Academic Press LLC; 1998.

17. Facione PA. California Critical Thinking Disposition Inventory. Milbrae, CA: California Academic Press; 1994.

18. Facione NC, Facione PA. The Health Sciences Reasoning Test: A test of Critical Thinking Skills for Health Care Professionals. Millbrae CA: California Academic Press LLC; 2006.

19. Feinstein AR. Clinical Judgment. St Louis, MO: CV Mosby; 1967.

20. Murphy EA. The Logic of Medicine. Second Edition. Baltimore, MD: The Johns Hopkins University Press; 1976. 1997.

21. Jenicek M. The Logic of Modern Medicine. Montreal: EPIMED International; 1995. Epidemiology.

22. Philips CI, editor. Logic in Medicine. London, England: BMJ Publishing Group; 1995.

23. Wulff HR, Pedersen SA, Rosenberg R. Philosophy of Medicine: An Introduction. Oxford, England: Blackwell Publishing; 1986.

24. Albert DA, Munson R, Resnik MD. Reasoning in Medicine: An Introduction to Causal Inference. Baltimore, MD: The Johns Hopkins University Press; 1988.

25. Sox JC, Jr, Blatt MA, Higgins MC, Morton KI. Medical Decision Making. Boston: Butterworths; 1988.

26. Eddy DM. A Collection of Essays from the Journal of the American Medical Association. Boston: Jones and Bartlett Publishers; 1996. Clinical Decision Making. From Theory to Practice.

27. Weinstein MC, Fineberg HV, Elstein AS, et al. Clinical Decision Analysis. Philadelphia: WB Saunders; 1980.

28. Kassirer JP, Kopelman RI. Learning Clinical Reasoning. Baltimore: Williams and Wilkins; 1991.

29. Hitchcock DL. A Guide to Evaluating Information. Toronto: Methuen Publishing; 1983. Critical Thinking.

30. Ennis RH. Critical Thinking. Upper Saddle River, NJ: Prentice-Hall; 1996.

31. Fisher A. An Introduction. Cambridge and New York: Cambridge University Press; 2001. Critical Thinking.

32. Thomson A. A Practical Introduction. 2nd edition. London and New York: Routledge; 2002. Critical Reasoning.

33. Bowell T, Kemp G. Critical Thinking A Concise Guide. 2nd Edition. London and New York: Routledge; 2002. 2007.

34. Paul R, Elder L. Critical and Creative Thinking. Dillon Beach, CA: The Foundation for Critical Thinking; 2004.

35. Jenicek M, Hitchcock DL. Evidence-Based Practice Logic and Critical Thinking in Medicine. Chicago: American Medical Association (AMA Press); 2005.

36. Jenicek M. A Physician’s Self-Paced Guide to Critical Thinking. Chicago: American Medical Association (AMA Press); 2006.

37. Jenicek M. Improving Communication and Decision Making in Research and Practice. Chicago: American Medical Association (AMA Press); 2009. Fallacy-Free Reasoning in Medicine.

38. Jenicek M. Understanding, Prevention, and Control. Boca Raton/London/New York: CRC Press/Taylor & Francis/Productivity Press; 2011. Medical Error and Harm.

39. Huth EJ. How to Write and Publish Papers in Medical Sciences. Philadelphia: iSi Press; 1982.

40. Huth EJ. Previously titled How to Write and Publish Papers in Medical Sciences. 3rd Edition. Baltimore, MD: Williams & Wilkins; 1999. Writing and Publishing in Medicine.

41. Horton R. The grammar of interpretive medicine. CMAJ. 1998;159:245–49.[PMC free article][PubMed]

42. Horton R. The rhetoric of research. BMJ. 1995;310:985–87.[PMC free article][PubMed]

43. Toulmin SE. The Uses of Argument. Cambridge, England: Cambridge University Press; 1958. (Updated edition, 2003)

44. Toulmin SE, Rieke R, Janik A. An Introduction to Reasoning. 2nd Edition. New York, NY: Collier Macmillan Publishers; 1984.

45. Dickinson HD. Evidence-based decision-making: an argumentative approach. Int J Med Informatics. 1998;51:71–81.[PubMed]

46. Kovacs G, Croskerry P. Clinical decision making. An emergency medicine perspective. Acad Emerg Med. 1999;6(9):947–52.[PubMed]

47. Sandhu H, Carpenter C. Critical decision making: Opening the black box of cognitive reasoning. Ann Emerg Med. 2006;48(6):713–19.[PubMed]

48. Croskerry P. A universal model for diagnostic reasoning. Acad Med. 2009;84:1022–28.[PubMed]

49. Paley J, Cheyne H, Dalgleish L, et al. Nursing’s way of knowing and dual process theories of cognition. J Adv Nursing. 2007;60:692–701.[PubMed]

50. Tooby J, Cosmides L. Conceptual foundations of evolutionary psychology. In: Buss DM, editor. The Handbook of Evolutionary Psychology. Hoboken, NJ: J Wiley & Sons; 2005. pp. 5–67.

51. Croskerry P. Clinical cognition and diagnostic error: applications of a dual process model of reasoning. Adv in Health Sci Educ. doi: 10.1007/s10459-009-9182-2.[PubMed][Cross Ref]

52. Hogarth RM. Educating Intuition. Chicago, Il: The University of Chicago Press; 2001.

53. Jenicek M. Foundations of Evidence-Based Medicine. Boca Raton, London, New York, Washington: The Parthenon Publishing group/CRC Press/Taylor & Francis; 2003.

54. Haburchak DR, Mitchell BC, Boomer CJ. Quixotic medicine: Physical and economic laws perilously disregarded in health care and medical education. Acad Med. 2008;83(12):1140–45.[PubMed]

55. Brancati FL. The art of pimping. JAMA. 1989;261(1):89–90.[PubMed]

56. Rao G. Rational Medical Decision Making: A Case-Based Approach. New York: McGraw Hill; 2007.

57. Croskerry P. Critical thinking and reasoning in emergency medicine. In: Croskerry P, Cosby KS, Schenkel SM, Wears RL, editors. Patient Safety in Emergency Medicine. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins; 2009. pp. 213–18.

58. Facione NC, Facione PA. Thinking and Reasoning in Human Decision Making: The method of Argument and Heuristic Analysis. Milbrae, CA: Insight Assessment/California Academic Press LLC; 2007.

59. Croskerry P. Context is everything or how could I have been so stupid? Healthcare Quarterly. 2009;12:e171–e177. Special Issue: Understanding Decision-Making in Healthcare and the Law. [PubMed]

60. Jenicek M. Towards evidence-based critical thinking medicine? Uses of best evidence in flawless argumentations. Med Sci Monit. 2006;12(8):RA149–53.[PubMed]

61. Jenicek M. How to read, understand, and write ‘Discussion’ sections in medical articles. An exercise in critical thinking. Med Sci Monit. 2006;12(6):SR28–36.[PubMed]

62. Jenicek M. Writing a ‘discussion’ section in a medical article: An exercise in critical thinking and argumentation. In: Jagadeesh G, Murthy S, Gupta YK, Prakash A, editors. Biomedical Research. From Ideation to Publication. Chapter 27. New Delhi/Philadelphia/Baltimore/New York/London/Buenos Aires/Hong Kong/Sydney/Tokyo: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2010. pp. 455–65.

63. Paton M. Reflective journals and critical thinking. UniServe Science Assessment Symposium Proceedings. 2006. pp. 97–100. at www.usyd.edu.au/su/SCH/pubs/procs/2006/paton.pdf, retrieved January 12, 2008.

64. Feinstein AR. What kind of basic science for clinical medicine? N Engl J Med. 1970;283:847–52.[PubMed]

65. Redelmeier DA, Ferris LE, Tu JV, et al. Problems of clinical judgment: introducing cognitive psychology as one more basic science. CMAJ. 2001;164(3):358–60.[PMC free article][PubMed]

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