Are scientisits immune from making logical fallacies?
Critical thinking is what makes a good scientist. But I have to admit that I never had a formal training on that subject and had to learn it by listening to an excellent podcast (http://www.theskepticsguide.org/). The lead podcaster Steven Novella has become for me a standard in logical thinking.
People promoting pseudo-sciences tend to make logical fallacies because they need to defend their believes by any means whatsoever. The worst and probably the most unpleasant fallacy is the so-called “ad hominem” where the person himself or herself is attacked instead of his or her arguments. This fallacy becomes nasty when specific aspects of that person are mentioned like the ethnicity or the gender.
Any scientist should aim at the highest standard and definitively stay away from making logical fallacies. Unfortunately when a scientific debate becomes too heated, scientists can lose their nerves and make fallacies. Are critical thinking and emotion incompatible? Someone can be passionate about his or her science but this is not an excuse for not keeping a cold head.