Good is a general term used to recommend or express approval in a wide range of contexts. Typically it means that something is worth choosing and may imply some positive feature of the thing concerned, such as a good restaurant or a good book. The word is also sometimes used to imply some kind of virtue, such as being virtuous. It is one of the most basic forms of evaluation, and is found in a wide range of languages.

Many philosophical issues depend on the concept of good. For example, some philosophers use it to distinguish ends, which are valued for their own sakes, from means, which are valued for the sake of the ends they promote. Others divide goods into intrinsic, or independent, and extrinsic, or agent-relative; the former are valued in themselves and the latter get their value from a person’s point of view.

Another important issue is what makes something a good. Historically, most philosophers have held that what makes something a good is its ability to serve some purpose. This explains why good and worth have been so central concepts to moral philosophy. However, in the past it has been argued that goodness and worth are different concepts. A number of people have attempted to explain this.

A common view in antiquity was that a good life required the possession of certain virtues, such as wisdom, justice, courage, and temperance. While there were some philosophers who tended toward hedonism (the Epicureans), most, including Aristotle, held that good was a matter of perfecting the human faculties.

More recently, Peter Geach has emphasized that goodness is a complex concept with numerous interpretations, making it difficult to determine what it is. He argues that although many people agree on what it is to be a good person, they disagree much more about which actions are good and which are bad.

Other philosophers have developed theories of good that aim to provide a more coherent and complete analysis than those of Moore and Geach. Franz Brentano developed an analysis of good that occupied a halfway point between Moore and naturalism; it was a complex, nonnatural property that could be determined by examining the effects of an action on the individual and the community. A. C. Ewing followed a similar line of reasoning, but his theory was ultimately unsatisfactory; the key concept, the notion of fittingness, was never fully elucidated.

In the present day, many of the same concerns continue to be debated, and a great deal of practical work depends on an understanding of the concept. For this reason, the topic is a core part of both academic and professional ethics. It is often a subject of popular discourse, as well, as it provides an important lens for viewing the world. It is therefore not surprising that good has remained a highly controversial and significant concept in many disciplines. This article was nominated for good status by WikiProject Ethics, and passed the good article criteria with minor revisions.

A bicycle is a small human powered land vehicle that has two wheels, a seat, and handlebars for steering. Millions of people worldwide ride bikes for fun, exercise, or transportation. A bicycle’s basic structure has changed little since its development in the 19th century, though modern materials and computer aided design have allowed for a wide range of specialized designs.

The bicycle is the most efficient human-powered means of transport, in terms of the amount of energy a person expends per unit of distance traveled. A typical bicycle transfers up to 99% of the energy put into the pedals into forward motion, with the remaining fraction used for balance and control.

Bicycles are built from a variety of materials, but most modern bicycles feature lightweight aluminum alloy frames and components. The use of these materials makes bicycles much more affordable than automobiles and other forms of motorized transportation, while also allowing designers to make lighter weight, stiffer, and more compliant vehicles.

The word “bicycle” is derived from the Latin words for two and wheel, and it has come to be the world’s most common means of transportation. Before the invention of the bicycle, humans moved around on foot or in animal-drawn carriages. In the 1860s, inventors began to add pedals to these animals, giving them greater speed and maneuverability. These early machines were called dandy horses, boneshakers, and velocipedes, but the term bicycle became popular by 1882, when the English writer Henry Lawson applied it to the machine he invented.

Other inventions soon followed, including better tires (which can be pneumatic or solid), better hand brakes, and a freewheel device that allows the back wheel to spin even when the rider is not pushing on the pedals. The freewheel device also enabled more complex gearing, allowing riders to travel over hills with less effort.

A bicycle may be equipped with a number of accessories for safety and comfort, such as headlights, reflectors, and fenders. Technical accessories, such as cyclocomputers, are also available to help riders monitor and optimize their performance. Some bicycles are fitted with hitches to carry cargo or a child seat.

The bicycle has become so common that it is now a very diverse form of transportation. People ride bicycles for recreation, in competitions such as BMX racing and criterium, and for fitness and transport. It has also become an important part of the infrastructure in some developing countries. Its widespread use has also resulted in the growth of related industries such as bicycle parts manufacturing and cycling tourism. In addition, the bicycle has helped develop advanced metalworking techniques that were later adapted for use in other technologies such as automobiles and aircraft.