As soon as we spot a thesis or hypothesis, we immediately search around for an example which refutes the thesis. According to Sir Karl Popper, the sole function of a hypothesis is to invite refutation because from the refutation will arise a better hypothesis. Clearly a single refutation will destroy the certainty of a hypothesis. A claim that all swans are white will be refuted by the first spotting of a black swan whereas to prove the hypothesis you would have to examine every single swan. There is a grave danger in this attitude. It excludes the provocative hypothesis, the function of which is to stimulate further exploration from which a better hypothesis will emerge. It also restricts us to absolute hypotheses rather than statistical ones and in some fields this can hold up progress. What we require from a hypothesis is a usable scan of predictions.

At least 20 million people have worked in a McDonald's since Ray Kroc opened his first McDonald's hamburger stand 40 years ago. Behind that number are several corporate strategies including using armies of part-time workers. In addition, hourly pay for McDonald's crew members is typically only a bit higher than the $5.25 minimum wage, and fringe benefits are meager. Employees leave so frequently that this year McDonald's and its franchisees, which employ more than 500,000 workers in the United States and Canada, will have to hire well over that number of new employees to stay fully staffed. But there is an upside to this upheaval. The fast-food chains have been forced to concentrate more than other businesses on training programs with an eye toward adapting large numbers of raw recruits.

The fourth industrial revolution will affect the scale of conflict as well as its character. The distinctions between war and peace and who is a combatant and noncombatant are becoming uncomfortably blurred. Similarly, the battlefield is increasingly both local and global. Organizations such as ISIS operate principally in defined areas in the Middle East but they also recruit fighters from more than a hundred countries, largely through social media, while related terrorist attacks can occur anywhere on the planet. Modern conflicts are increasingly hybrid in nature, combining traditional battlefield techniques with elements that were previously mostly associated with armed non-state actors. However, with technologies fusing in increasingly unpredictable ways and with state and armed non-state actors learning from each other, the potential magnitude of change is not yet widely appreciated.

When you begin to tell a story again that you have retold many times, what you retrieve from memory is the index to the story itself. That index can be embellished in a variety of ways. Over time, even the embellishments become standardized. An old man's story that he has told hundreds of times shows little variation, and any variation that does exist becomes part of the story itself, regardless of its origin. People add details to their stories that may or may not have occurred. They are recalling indexes and reconstructing details. If at some point they add a nice detail, not really certain of its validity, telling the story with that same detail a few more times will ensure its permanent place in the story index. In other words, the stories we tell time and again are identical to the memory we have of the events that the story relates.

One of the common themes of the Western philosophical tradition is the distinction between sensual perceptions and rational knowledge. Since Plato, the supremacy of rational reason is based on the assertion that it is able to extract true knowledge from experience. As the discussion in the Republic helps to explain, perceptions are inherently unreliable and misleading because the senses are subject to errors and illusions. Only the rational discourse has the tools to overcome illusions and to point towards true knowledge. For instance, perception suggests that a figure in the distance is smaller than it really is. Yet, the application of logical reasoning will reveal that the figure only appears small because it obeys the laws of geometrical perspective. Nevertheless, even after the perspectival correction is applied and reason concludes that perception is misleading, the figure still appears small, and the truth of the matter is revealed not in the perception of the figure but in its rational representation.

There are at least two reasons why a subjective sense of "foreign-ness" may implicitly suggest the possibility of spreading disease. First, historically, contact with exotic peoples increased exposure to exotic germs, which tend to be especially contagious when introduced to the local population. Secondly, outsiders are often ignorant of local behavioral norms that serve as barriers to germ transmission (e.g., norms pertaining to hygiene, food-preparation); as a consequence, they may be more likely to violate these norms, thereby increasing the danger of germ transmission within the local population. Thus, in addition to other risks suggested by outgroup status, people perceived to be subjectively foreign are likely to be implicitly judged to pose the threat of infection.

One of the great risks of writing is that even the simplest of choices regarding wording or punctuation can sometimes prejudice your audience against you in ways that may seem unfair. For example, look again at the old grammar rule forbidding the splitting of infinitives. After decades of telling students to never split an infinitive (something just done in this sentence), most composition experts now acknowledge that a split infinitive is not a grammar crime. Suppose you have written a position paper trying to convince your city council of the need to hire security personnel for the library, and half of the council members ― the people you wish to convince ― remember their eighth-grade grammar teacher's warning about splitting infinitives. How will they respond when you tell them, in your introduction, that librarians are compelled "to always accompany" visitors to the rare book room because of the threat of damage? How much of their attention have you suddenly lost because of their automatic recollection of what is now a nonrule? It is possible, in other words, to write correctly and still offend your readers' notions of your language competence.

Examples of the inability to reason well abound. It is not uncommon to find analysts failing to distinguish between facts and inferences or operating on the assumption that an inference was a fact. It is not unusual to hear an analyst state that his conclusions followed "logically" from the evidence, even though generalizations arrived at inductively are not subject to logical proof. That different types of inquiry are subject to different types of "proof" is an alien concept to many researchers. And the common misuse of infer and imply reflects not only a lack of knowledge of terminology but also an unfamiliarity with underlying concepts of logic as well.

Common law is otherwise known as case law, which is the law developed by the judges in their judgments (or rulings) on particular cases. The judges are guided by the theory and rules of precedent, which means they are bound by previous rulings that set "precedents." This essentially means that they must take into account similar cases decided in the past, particularly those decided in the highest courts. This area of judge-made law is important because there will be situations where Parliament has not enacted a law and it falls to the judges to plug the gap. Equally, judges must sometimes interpret laws that Parliament has passed. One such example involved the Abortion Act 1967. A secretary declined to type a referral letter for a termination, claiming that the right to conscientiously object to participation in an abortion protected her refusal. The judges looked at the word "participation" and decided that the secretary was not covered, as she was not sufficiently involved in the procedure.

In everyday life, we tend to see any collection of people as a group. However, social psychologists use this term more precisely. In particular, they define a group as two or more people who interact with, and exert mutual influences on, each other. It is this sense of mutual interaction or inter-dependence for a common purpose which distinguishes the members of a group from a mere aggregation of individuals. For example, as Kenneth Hodge observed, a collection of people who happen to go for a swim after work on the same day each week does not, strictly speaking, constitute a group because these swimmers do not interact with each other in a structured manner. By contrast, a squad of young competitive swimmers who train every morning before going to school is a group because they not only share a common objective (training for competition) but also interact with each other in formal ways (e.g., by warming up together beforehand). It is this sense of people coming together to achieve a common objective that defines a "team".

Initially seen as miracle drugs, antibiotics, once they became widely available, were used not only for bacterial infections, but for everything from the common cold to headaches. Indeed antibiotics were a godsend, drastically improving medicine and contributing significantly to the increase in life expectancy achieved during the twentieth century. Like many technological fixes, along with the positive benefits of antibiotics came negative side effects. Antibiotics can kill the many beneficial bacteria in the human body, for instance those that promote digestion, along with invasive bacteria. Another, unexpected, consequence is the ability of bacteria to overcome the mechanisms that give antibiotics their efficacy, rendering them useless. Antibiotic resistance, first a curiosity seen in the laboratory, became common among populations of bacteria exposed to antibiotics. In a matter of years following the introduction of penicillin, penicillin-destroying staphylococci appeared in hospitals where much of the early use of penicillin had taken place.

Dr. Zeray Alemseged made a remarkable contribution to the field of anthropology. Inspired by his experience of working in Ethiopia's National Museum, Alemseged went to the University of Paris for a Ph.D. program. After he returned to Ethiopia, he set his sight on an isolated region as an optimal place to look for new fossils. Other scientists had avoided this area, due to a centuries-old tribal conflict that made it too dangerous to work in, but he did not give up convincing both sides to allow him to work there. Alemseged and his team finally discovered the fossilized skeleton of a 3.3 million-year-old baby girl. It included the shoulder blades almost intact, which had never been found fossilized as they are paper-thin. Based on the shape of these blades, Alemseged and his colleagues published a study suggesting that Australopithecus afarensis was still a capable climber 3.3 million years ago, which means our ancestors gave up tree-climbing considerably later than many researchers had previously suggested.