By their very nature, the social sciences are the product of logic, rationality and reason in the study of the individual and/or the group. When logic and rationality break down, are abandoned, or are manipulated to gain the desired outcomes, the integrity, success, and reliability of understandings is questioned and the legitimacy of the science itself can be challenged.
Logical fallacies are legion. They are easy to learn and to understand, but they are not always easy to detect. Any student of the social, interpersonal, and behavorial sciences must have an understanding of the basics of logical fallacy, whether it is to determine if there is a flaw in the reasoning; to provide sound support for argument in favor of a proposition; or to challenge an argument, experiment or proposition.
The logical fallacies evolve in terminology, definition and title over time, but the form and function remains as classical entities that can be expressed, defined and identified. There may be several names for a well known logical fallacy, implying that there are different versions of the fallacy, but there may or may not be any true variation from the classic form.
Logical fallacies range from obvious and basic in nature, to obscure and difficult to to break down and to identify. Logical fallacies can stem from complex linguistic game playing, or from manipulations of complex statistical models and calculations. In some cases, the fallacy lies in interpretations of someone elses work, with the fallacy falsely attributed to the wrong person.
It is important to understand the ways in which a statement appears to be fallacious, but is not a fallacy. In some forms of argument, the ad hominem, or personal attack may be a fallacy or it may be the function of the speaker to point out the personal charistics of the opponent and bring them up for discussion. In political campaigns, candidates must be examined for personal qualities and they must answer questions their character and personal qualities. In a scientific discussion, it is more difficult to justify a character attack that is only to serve as a distraction from the factual material that is being presented.
Some of the basic components of an argument are fact, evidence, proof, premise, assumption, relationship, language, cause, effect, chain of cause and effect, accusation, claim, defense, prediction, and conclusion.
In some logical fallacies, the facts/proof/evidence are manipulated, are false, are misunderstood and misrepresented, or the speaker avoids meeting the requirement to provide all (not just the part that supports his or her proposal) of the proof and evidence, to tell the truth, or to relate the facts to the topic at hand. The form is that A is true, trust me!
In some logical fallacies, the relationship, cause and effect, and predictions are based on flawed evidence. Relationships are claimed when they do not exist. There may not be a cause and effect, or the change in A may have a negligible effect on B. Therefore, predictions based on flawed cause and effect or relationship assumptions are also flawed. The social scientist must make serious effort to ensure that relationships are well defined, well tested and that the effects are accurately measured.
In the above logical fallacy, the social scientist must construct sound hypotheses. The next aspect of hypothetical logical fallacies fall into the quantification category, where there are flaws in the ways in which natural phenomena or human endeavor is represented by assigned numerical values. Some numerical values, such as record number, are not to contain any data or the large database design can be seriously compromised. A sample size that is far too small to allow conclusions that apply to the general population is a fatal flaw.
In logical fallacies that avoid the existence of conditionality or of conditions, the social scientist should be alarmed! Human existence is riddled with "Else", "Or" , "and", "then" and "If" conditions which may be more important or successful in explaining, arguing, forming assumptions, making premises, proposing, predicting or concluding. The else/or/and/if is at the core of internal and external validity in the social experiment.
In other logical fallacies, unsolvable paradoxes are solved by poor methods. When there is a continuum, it is difficult to justify some categories or divisions. The fallacies of the beard and the heap illustrate how, since it is impossible to call a specific length of facial hair or a specific number or grains an official "beard" or "heap", then beards or heaps do not exist! The Social scientist must exercise extreme effort when attempting to divide a continuum into meaningful categories.
As a result, it is important for the social scientist to study, understand, and to gain skills in identifying logical flaws, faults and fallacies. The Internet Encyclopedia of Philosophy has an excellent resource for understanding the logical fallacies at a basic level.