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USA Edition | Today Is Friday, May 24, 2013 |
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Socratic Warning
Newsroom Magazine
May Challenge
Or Demand
Critical Thinking
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The intellectual roots of critical thinking date back to the Greek philosophers.
Socrates discovered, by means of probing questions, that in the exchange of competing ideas, people sometimes make confident claims based on unreliable assumptions or failed logic.
Such arguments, he discovered, were either erroneous in fact, absent sufficient foundation, or failing in logic. Instead, most arguments were based on confused meanings, inadequate evidence, or contradictory beliefs.
Socrates' contributions to critical thinking were many -- for he established new ways to think about contentious issues in terms of the quality of assumptions, facts and logic.
Thus Socrates demonstrated that persons may have passion, or power or high position but yet be deeply confused and irrational.
Good journalism, like compelling debate, is based on a clear understanding of facts and the logical construction of one's argument. And that is what the Socratic Method and The Sophist Tradition is all about.
Evidentiary Approach
The Socratic Method is the preferred way to examine issues.In the Socratic mode of questioning, postulations, ideas or arguments are examined for their clarity and logical consistency by systematic analysis of facts, assumptions and logical methodology to support a conclusion.
Socratic analysis is accomplished by means of a series of probing questions that systematically examine the quality of an argument or conclusion.
Understanding the quality of information, argument or one's conclusions, is fundamental to critical thinking -- and the goal of critical editing.
Historical Foundation
Socrates’ practice was followed by the critical thinking of Plato (who recorded Socrates’ thought), Aristotle, and the Greek skeptics, all of whom emphasized that things are often very different from what they appear to be.Only the trained mind is prepared to see through the way things look to us on the surface (delusive appearances) to the way they really are beneath the surface (the deeper realities of life.)
From this ancient Greek tradition emerged the need, for anyone who aspired to understand the deeper realities, to think systematically, to trace implications broadly and deeply; for only thinking that is comprehensive, well-reasoned, and responsive to objections can take us beyond the surface.
Means Of Analysis
The common denominators of Critical Thinking requires, for example, the systematic monitoring of thought; that thinking, to be critical, must not be accepted at face value, but must be analyzed and assessed for its clarity, accuracy, relevance, depth, breadth, and logical validity. All reasoning occurs within points of view and frames of reference.All reasoning proceeds from some goals, objectives, and has an informational base. All data, when used in reasoning, must be interpreted. That interpretation involves concepts, that concepts entail assumptions, and that all basic inferences in thought have implications, and each of these dimensions of thinking need to be monitored where problems of thinking can occur.
Questioning Chain
The result of the collective contribution of the history of critical thought is that the basic questions of Socrates can now be much more powerfully and focally framed.In every domain of human thought, and within every use of reasoning within any domain, it is now possible to question:
• ends and objectives
• the status and wording of questions
• the sources of information and fact
• the method and quality of information collection
• the mode of judgment and reasoning used
• the concepts that make that reasoning possible
• the assumptions that underlie concepts in use
• the implications that follow from their use
• the point of view or frame of reference within which reasoning takes place
Jeffrey Slee
Logician
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In a study that spanned almost 20 years, researchers found that overall colorectal cancer mortality (deaths) was reduced by 26 percent and incidence (new cases) was reduced by 21 percent as a result of screening with sigmoidoscopy.
Washington
NIH Study Finds Sigmoidoscopy Reduces Colorectal Cancer Rates
May 21, 2012
Figure 1: A thin, lighted tube is inserted through the anus and rectum and into the lower part of the colon to look for abnormal areas. Credit: Terese Winslow for NCI
Flexible sigmoidoscopy, a screening test for colorectal cancer that is less invasive and has fewer side effects than colonoscopy, is effective in reducing the rates of new cases and deaths due to colorectal cancer, according to research sponsored by the National Cancer Institute, part of the National Institutes of Health.
In a study that spanned almost 20 years, researchers found that overall colorectal cancer mortality (deaths) was reduced by 26 percent and incidence (new cases) was reduced by 21 percent as a result of screening with sigmoidoscopy. These results appeared online, ahead of print, on May 21, 2012, in the New England Journal of Medicine, and were presented at Digestive Disease Week, a scientific conference.
Sigmoidoscopy involves examination of the lower colon using a thin, flexible tube-like instrument, called a sigmoidoscope, to view the anus, rectum, and sigmoid colon (see Figure 1). Sigmoidoscopy has fewer side effects, requires less bowel preparation, and poses a lower risk of bowel perforation (an uncommon event, when the screening instrument pokes a hole in the intestine) than colonoscopy, in which a similarly flexible, but longer, tube is used to view the entire colon.
Colorectal cancer is the second-leading cause of cancer-related death in the United States. Previous research has shown that colorectal cancer incidence and mortality can be reduced with a number of screening methods, including fecal occult blood testing (FOBT).
However, flexible sigmoidoscopy and colonoscopy are more sensitive than FOBT for detecting polyps (see Figure 2) that may lead to colorectal cancer. Removal of pre-cancerous polyps, which can be done during sigmoidoscopy or colonoscopy, reduces colorectal cancer risk.
“The most important message is that, regardless of modality chosen, colorectal cancer screening lowers mortality from colorectal cancer, and all individuals 50 and over should be screened,” said study author Christine Berg, M.D., chief of NCI’s Early Detection Research Group and project officer of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.
From 1993 to 2001, a total of 154,900 men and women aged 55 through 74 were randomly assigned to receive flexible sigmoidoscopy screening or usual care as part of the PLCO trial. People in the usual care group (i.e. control group) only received screening if they asked for it, or if their physician recommended it.
This large population-based randomized trial was designed to determine the effects of screening on cancer-related mortality. Participants assigned to the flexible sigmoidoscopy group were screened once on entering the study (baseline) and again three years to five years later. The participants were followed for approximately 12 years to collect data on cancer diagnoses and deaths (additional background on PLCO).
The researchers compared overall colorectal cancer mortality and incidence in the two groups, and also analyzed incidence and mortality according to the location of the cancers that developed. Cancers located from the rectum through a bend in the colon called the splenic flexure (see Figure 3) were defined as distal, and those in the transverse colon to the cecum were defined as proximal. Although flexible sigmoidoscopy examines only the rectum and sigmoid colon, participants with a suspicious finding were referred for a follow-up colonoscopy, in which both the distal and proximal regions of the colon would be examined.
Figure 2: Colon polyps are growths that can lead to colon cancer. They can be flat or have stalks as show. Credit: Terese Winslow for NCI
Overall, after an average of nearly 12 years, participants in the screening group had a 21 percent lower incidence of colorectal cancer overall and a 26 percent lower rate of colorectal cancer mortality than participants in the usual care group.
This means that, over the course of 10 years, if 1,000 people followed the PLCO protocol of two sigmoidoscopy screenings, there would be approximately three fewer new cases and one fewer death from colorectal cancer than in a comparable group not receiving regular screenings.
The incidence of distal colorectal cancer was reduced by 29 percent, and mortality from distal colorectal cancer was reduced by 50 percent, in the screening group. While there was no statistically significant decline in deaths from proximal colorectal cancer, the incidence of proximal colorectal cancer was reduced by 14 percent in the screening group.
“This is the second major trial that has shown that sigmoidoscopy is effective in reducing the risk of dying of colorectal cancer. Sigmoidoscopy is less invasive than colonoscopy and carries a lower risk of the colon being perforated, which may make it more acceptable as a screening test to some patients,” said Barnett Kramer, M.D., director of NCI’s Division of Cancer Prevention. “There are several effective screening tests for colorectal cancer, and the most effective screening test is the one that people choose to take.”
Screening by sigmoidoscopy detected 24 percent of the colorectal cancers that were diagnosed in the screening group. Another 60 percent were detected by symptoms or by screening performed outside of the PLCO protocol or were found more than one year after a screening exam — the cutoff for defining a cancer as screen detected — in participants who had at least one screening exam, and the remaining 16 percent developed in participants assigned to the screening group who never actually underwent screening.
Of the colorectal cancers that were detected by screening, nearly 83 percent were found in the distal colon, whereas distal colorectal cancers made up about 53 percent of the cancers in people in the screening group who were never screened and about 32 percent of cancers in people who underwent screening but whose cancers were not detected by screening. Cancers detected by screening were more likely to be early stage (75 percent were stage I or II) than cancers that weren’t detected by screening (51 percent were stage I or II).
Screening was associated with reductions in incidence and mortality for all stages of distal colorectal cancer. However, in the proximal colon, reductions in incidence were only seen in stages I, II, and III, and there was no impact on proximal colorectal cancer mortality.
Figure 3: Segments of the digestive tract
The researchers estimated that if they had used colonoscopy rather than sigmoidoscopy in this study, they would have identified 16 percent more cancers, two-thirds of which would have been proximal cancers.
However, they were not able to determine what effect that may have had on proximal colorectal cancer mortality. There has been some controversy about how effective colonoscopy is in decreasing colorectal cancer mortality in different regions of the colon, with some studies suggesting that it is more effective against distal than proximal tumors. Sigmoidoscopy has never been directly compared to colonoscopy in a definitive clinical trial.
False-positive sigmoidoscopy results were observed in 20 percent of men and 13 percent of women in the screening group, but some of these false positives could have been the result of false-negative colonoscopies done to follow up on suspicious sigmoidoscopy findings. Approximately 22 percent of people in the screening group were sent for follow-up colonoscopies during the screening phase of the trial.
