Thomas Robert Malthus in the context of "Malthusian catastrophe"

Classical economics, also known as the classical school of economics, or classical political economy, is a school of thought in political economy that flourished, primarily in Britain, in the late 18th and early-to-mid 19th century. It includes both the Smithian and Ricardian schools. Its main thinkers are held to be Adam Smith, Jean-Baptiste Say, David Ricardo, Thomas Robert Malthus, and John Stuart Mill. These economists produced a theory of market economies as largely self-regulating systems, governed by natural laws of production and exchange (famously captured by Adam Smith's metaphor of the invisible hand).

Adam Smith's The Wealth of Nations in 1776 is usually considered to mark the beginning of classical economics. The fundamental message in Smith's book was that the wealth of any nation was determined not by the gold in the monarch's coffers, but by its national income. This income was in turn based on the labor of its inhabitants, organized efficiently by the division of labour and the use of accumulated capital, which became one of classical economics' central concepts.

The book An Essay on the Principle of Population was first published anonymously in 1798, but the author was soon identified as Thomas Robert Malthus. The book warned of future difficulties, on an interpretation of the population increasing in geometric progression (so as to double every 25 years) while food production increased in an arithmetic progression, which would leave a difference resulting in the want of food and famine, unless birth rates decreased.

While it was not the first book on population, Malthus's book fuelled debate about the size of the population in Britain and contributed to the passing of the Census Act 1800. This Act enabled the holding of a national census in England, Wales and Scotland, starting in 1801 and continuing every ten years to the present. The book's 6th edition (1826) was independently cited as a key influence by both Charles Darwin and Alfred Russel Wallace in developing the theory of natural selection.

The concept of the struggle for existence (or struggle for life) concerns the competition or battle for resources needed to live. It can refer to human society, or to organisms in nature. The concept is ancient, and the term struggle for existence was in use by the end of the 18th century. From the 17th century onwards the concept was associated with a population exceeding resources, an issue shown starkly in Thomas Robert Malthus’ An Essay on the Principle of Population which drew on Benjamin Franklin's Observations Concerning the Increase of Mankind, Peopling of Countries, etc..

It is sometimes forgotten that Charles Darwin used the term "struggle for existence" in what he called a metaphorical sense. This was because he used it to refer not only to direct competition between (and within) species but indirect competition (as with a plant at the edge of the desert). Darwin noted that the struggle for existence could also involve active or passive mutual aid between organisms of the same or different species, instancing social insects (see also symbiosis).

Conflict theories are perspectives in political philosophy and sociology which argue that individuals and groups (social classes) within society interact on the basis of conflict rather than agreement, while also emphasizing social psychology, historical materialism, power dynamics, and their roles in creating power structures, social movements, and social arrangements within a society. Conflict theories often draw attention to power differentials, such as class conflict, or a conflict continuum. Power generally contrasts historically dominant ideologies, economies, currencies or technologies. Accordingly, conflict theories represent attempts at the macro-level analysis of society.

Many political philosophers and sociologists have been framed as having conflict theories, dating back as far as Plato's idea of the tripartite soul of The Republic, to Hobbes' ideas in The Leviathan. Other historical political philosophers associated with having "conflict theories" include Jean Bodin, Adam Smith, John Stuart Mill, Thomas Robert Malthus, Karl Marx, and Georg Simmel. Georg Simmel was one of the earliest sociologists to formally use "conflict" as a framework to understand social change, writing about the topic in his 1908 book, "Conflict and the Web of Group Affiliations".

Malthusianism is a theory that population growth is potentially exponential, according to the Malthusian growth model, while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population decline. This event, called a Malthusian catastrophe (also known as a Malthusian trap, population trap, Malthusian check, Malthusian snatch, Malthusian crisis, point of crisis, or Malthusian crunch) has been predicted to occur if population growth outpaces agricultural production, thereby causing famine or war. According to this theory, poverty and inequality will increase as the price of assets and scarce commodities goes up due to fierce competition for these dwindling resources. This increased level of poverty eventually causes depopulation by decreasing birth rates. If asset prices keep increasing, social unrest would occur, which would likely cause a major war, revolution, or a famine. Societal collapse is an extreme but possible outcome from this process. The theory posits that such a catastrophe would force the population to "correct" back to a lower, more easily sustainable level (quite rapidly, due to the potential severity and unpredictable results of the mitigating factors involved, as compared to the relatively slow time scales and well-understood processes governing unchecked growth or growth affected by preventive checks). Malthusianism has been linked to a variety of political and social movements, but almost always refers to advocates of population control.

These concepts derive from the political and economic thought of the Reverend Thomas Robert Malthus, as laid out in his 1798 writings, An Essay on the Principle of Population. Malthus suggested that while technological advances could increase a society's supply of resources, such as food, and thereby improve the standard of living, the abundance of resources would enable population growth, which would eventually bring the supply of resources for each person back to its original level. Some economists contend that since the Industrial Revolution in the early 19th century, mankind has broken out of the trap. Others argue that the continuation of extreme poverty indicates that the Malthusian trap continues to operate. Others further argue that due to lack of food availability coupled with excessive pollution, developing countries show more evidence of the trap as compared to developed countries. A similar, more modern concept, is that of human overpopulation.

David Ricardo (18 April 1772 – 11 September 1823) was a British economist and politician of Portuguese Jewish descent. He is recognized as one of the most influential classical economists, alongside figures such as Thomas Malthus, Adam Smith and James Mill.

Ricardo was born in London as the third surviving child of a successful stockbroker and his wife. He came from a Sephardic Jewish family of Portuguese origin. At 21, he eloped with a Quaker and converted to Unitarianism, causing estrangement from his family. He made his fortune financing government borrowing and later retired to an estate in Gloucestershire. Ricardo served as High Sheriff of Gloucestershire and bought a seat in Parliament as an earnest reformer. He was friends with prominent figures like James Mill, Jeremy Bentham, and Thomas Malthus, engaging in debates over various topics. Ricardo was also a member of The Geological Society, and his youngest sister was an author.