According to many definitions, a disability is an impairment that may be cognitive, intellectual, physical, sensory, or some combination of these. Other definitions describe disability as the societal disadvantage arising from such impairments. Disability affects a person's life activities and may be present from birth or occur during a person's lifetime. Disabilities is an umbrella term, covering impairments, activity limitations, participation restrictions. An impairment is a problem in body structure. Disability is thus not just a health problem, it is a complex phenomenon, reflecting the interaction between features of a person’s body and features of the society in which he or she lives. Disability is a contested concept, with different meanings in different communities, it may be used to refer to physical or mental attributes that some institutions medicine, view as needing to be fixed. It may refer to limitations imposed on people by the constraints of an ableist society. Or the term may serve to refer to the identity of disabled people.
Physiological functional capacity is a related term that describes an individual's performance level. It gauges one's ability to perform the physical tasks of daily life and the ease with which these tasks are performed. PFC declines with advancing age to result in frailty, cognitive disorders or physical disorders, all of which may lead to labeling individuals as disabled; the discussion over disability's definition arose out of disability activism in the United States and the United Kingdom in the 1970s, which challenged how the medical concept of disability dominated perception and discourse about disabilities. Debates about proper terminology and their implied politics continue in disability communities and the academic field of disability studies. In some countries, the law requires that disabilities are documented by a healthcare provider in order to assess qualifications for disability benefits. For the purposes of the Americans with Disabilities Act of 1990, the Equal Employment Opportunity Commission regulations provide a list of conditions that should be concluded to be disabilities: deafness, blindness, an intellectual disability or missing limbs or mobility impairments requiring the use of a wheelchair, cancer, cerebral palsy, epilepsy, Human Immunodeficiency Virus infection, multiple sclerosis, muscular dystrophy, major depressive disorder, bipolar disorder, post-traumatic stress disorder, obsessive compulsive disorder, schizophrenia.
Contemporary understandings of disability derive from concepts that arose during the West's scientific Enlightenment. During the Middle Ages and other conditions were thought to be caused by demons, they were thought to be part of the natural order during and in the fallout of the Plague, which wrought impairments throughout the general population. In the early modern period there was a shift to seeking biological causes for physical and mental differences, as well as heightened interest in demarcating categories: for example, Ambroise Pare, in the sixteenth century, wrote of "monsters", "prodigies", "the maimed"; the European Enlightenment's emphases on knowledge derived from reason and on the value of natural science to human progress helped spawn the birth of institutions and associated knowledge systems that observed and categorized human beings. Contemporary concepts of disability are rooted in eighteenth- and nineteenth-century developments. Foremost among these was the development of clinical medical discourse, which made the human body visible as a thing to be manipulated and transformed.
These worked in tandem with scientific discourses that sought to classify and categorize and, in so doing, became methods of normalization. The concept of the "norm" developed in this time period, is signaled in the work of the Belgian statistician, sociologist and astronomer Adolphe Quetelet, who wrote in the 1830s of l'homme moyen – the average man. Quetelet postulated that one could take the sum of all people's attributes in a given population and find their average, that this figure should serve as a norm toward which all should aspire; this idea of a statistical norm threads through the rapid take up of statistics gathering by Britain, United States, the Western European states during this time period, it is tied to the rise of eugenics. Disability, as well as other concepts including: abnormal, non-normal, normalcy came from this; the circulation of these concepts is evident in the popularity of the freak show, where showmen profited from exhibiting people who deviated from those norms.
With the rise of eugenics in the latter part of the nineteenth century, such deviations were viewed as dangerous to the health of entire populations. With disability viewed as part of a person's biological make-up and thus their genetic inheritance, scientists turned their attention to notions of weeding such "deviations" out of the gene pool. Various metrics for assessing a person's genetic fitness, which were used to deport, sterilize, or institutionalize those deemed unfit. At the end of the Second World War, with the example of Nazi eugenics, eugenics faded from public discourse, d
Violence is "the use of physical force so as to injure, damage, or destroy." Less conventional definitions are used, such as the World Health Organization's definition of violence as "the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community, which either results in or has a high likelihood of resulting in injury, psychological harm, maldevelopment, or deprivation."Globally, violence resulted in the deaths of an estimated 1.28 million people in 2013 up from 1.13 million in 1990. Of the deaths in 2013 842,000 were attributed to self-harm, 405,000 to interpersonal violence, 31,000 to collective violence and legal intervention. In Africa, out of every 100,000 people, each year an estimated 60.9 die a violent death. For each single death due to violence, there are dozens of hospitalizations, hundreds of emergency department visits, thousands of doctors' appointments. Furthermore, violence has lifelong consequences for physical and mental health and social functioning and can slow economic and social development.
In 2013, assault by firearm was the leading cause of death due to interpersonal violence, with 180,000 such deaths estimated to have occurred. The same year, assault by sharp object resulted in 114,000 deaths, with a remaining 110,000 deaths from personal violence being attributed to other causes. Violence in many forms can be preventable. There is a strong relationship between levels of violence and modifiable factors in a country such as concentrated poverty and gender inequality, the harmful use of alcohol, the absence of safe and nurturing relationships between children and parents. Strategies addressing the underlying causes of violence can be effective in preventing violence, although mental and physical health and individual responses, etc. have always been decisive factors in the formation of these behaviors. The World Health Organization divides violence into three broad categories: self-directed violence interpersonal violence collective violenceThis initial categorization differentiates between violence a person inflicts upon himself or herself, violence inflicted by another individual or by a small group of individuals, violence inflicted by larger groups such as states, organized political groups, militia groups and terrorist organizations.
These three broad categories are each divided further to reflect more specific types of violence: physical sexual psychological emotionalAlternatively, violence can be classified as either instrumental or reactive / hostile. Self-directed violence is subdivided into suicidal self-abuse; the former includes suicidal thoughts, attempted suicides – called para suicide or deliberate self-injury in some countries – and completed suicides. Self-abuse, in contrast, includes acts such as self-mutilation. Collective violence is subdivided into economic violence. Unlike the other two broad categories, the subcategories of collective violence suggest possible motives for violence committed by larger groups of individuals or by states. Collective violence, committed to advance a particular social agenda includes, for example, crimes of hate committed by organized groups, terrorist acts and mob violence. Political violence includes war and related violent conflicts, state violence and similar acts carried out by larger groups.
Economic violence includes attacks by larger groups motivated by economic gain – such as attacks carried out with the purpose of disrupting economic activity, denying access to essential services, or creating economic division and fragmentation. Acts committed by larger groups can have multiple motives; this typology, while imperfect and far from being universally accepted, does provide a useful framework for understanding the complex patterns of violence taking place around the world, as well as violence in the everyday lives of individuals and communities. It overcomes many of the limitations of other typologies by capturing the nature of violent acts, the relevance of the setting, the relationship between the perpetrator and the victim, – in the case of collective violence – possible motivations for the violence. However, in both research and practice, the dividing lines between the different types of violence are not always so clear. State violence involves upholding, forms of violence of a structural nature, such as poverty, through dismantling welfare, creating strict policies such as'welfare to work', in order to cause further stimulation and disadvantage Poverty as a form of violence may involve oppressive policies that target minority or low socio-economic groups.
The'war on drugs', for example, rather than increasing the health and well-being of at risk demographics, most results in violence committed against these vulnerable demographics through incarceration and police brutality War is a state of prolonged violent large-scale conflict involving two or more groups of people under the auspices of government. It is the most extreme form of collective violence. War is fought as a means of resolving territorial and other conflicts, as war of aggression to conquer territory or loot resources, in national self-defence or liberation, or to suppress attempts of part of the nation to secede from it. There are ideological and revolutionary wars. Since the Industrial Revolution the lethality of modern warfare has grown. World War I casualties were over 40 million and World War II casualties were over 70 million. Violence includes those acts that result from a power relationship, including threats and intimidation, neglect or acts of omission; such non-physical violence has
Hippocrates of Kos known as Hippocrates II, was a Greek physician of the Age of Pericles, considered one of the most outstanding figures in the history of medicine. He is referred to as the "Father of Medicine" in recognition of his lasting contributions to the field as the founder of the Hippocratic School of Medicine; this intellectual school revolutionized medicine in ancient Greece, establishing it as a discipline distinct from other fields with which it had traditionally been associated, thus establishing medicine as a profession. However, the achievements of the writers of the Corpus, the practitioners of Hippocratic medicine and the actions of Hippocrates himself were commingled. Hippocrates is portrayed as the paragon of the ancient physician, credited with coining the Hippocratic Oath, still relevant and in use today, he is credited with advancing the systematic study of clinical medicine, summing up the medical knowledge of previous schools, prescribing practices for physicians through the Hippocratic Corpus and other works.
Historians agree. Soranus of Ephesus, a 2nd-century Greek physician, was Hippocrates' first biographer and is the source of most personal information about him. Biographies are in the Suda of the 10th century AD, in the works of John Tzetzes, Aristotle's "Politics", which date from the 4th century BC. Soranus wrote that Hippocrates' father was Heraclides, a physician, his mother was Praxitela, daughter of Tizane; the two sons of Hippocrates and Draco, his son-in-law, were his students. According to Galen, a physician, Polybus was Hippocrates' true successor, while Thessalus and Draco each had a son named Hippocrates. Soranus said that Hippocrates learned medicine from his father and grandfather, studied other subjects with Democritus and Gorgias. Hippocrates was trained at the asklepieion of Kos, took lessons from the Thracian physician Herodicus of Selymbria. Plato mentions Hippocrates in two of his dialogues: in Protagoras, Plato describes Hippocrates as "Hippocrates of Kos, the Asclepiad". Hippocrates taught and practiced medicine throughout his life, traveling at least as far as Thessaly and the Sea of Marmara.
Several different accounts of his death exist. He died in Larissa, at the age of 83, 85 or 90, though some say he lived to be well over 100. Hippocrates is credited with being the first person to believe that diseases were caused not because of superstition and gods. Hippocrates was credited by the disciples of Pythagoras of allying medicine, he separated the discipline of medicine from religion and arguing that disease was not a punishment inflicted by the gods but rather the product of environmental factors and living habits. Indeed there is not a single mention of a mystical illness in the entirety of the Hippocratic Corpus. However, Hippocrates did work with many convictions that were based on what is now known to be incorrect anatomy and physiology, such as Humorism. Ancient Greek schools of medicine were split on; the Knidian school of medicine focused on diagnosis. Medicine at the time of Hippocrates knew nothing of human anatomy and physiology because of the Greek taboo forbidding the dissection of humans.
The Knidian school failed to distinguish when one disease caused many possible series of symptoms. The Hippocratic school or Koan school achieved greater success by applying general diagnoses and passive treatments, its focus was on patient prognosis, not diagnosis. It could treat diseases and allowed for a great development in clinical practice. Hippocratic medicine and its philosophy are far removed from that of modern medicine. Now, the physician focuses on specific diagnosis and specialized treatment, both of which were espoused by the Knidian school; this shift in medical thought since Hippocrates' day has caused serious criticism over the past two millennia, with the passivity of Hippocratic treatment being the subject of strong denunciations. Another important concept in Hippocratic medicine was that of a crisis, a point in the progression of disease at which either the illness would begin to triumph and the patient would succumb to death, or the opposite would occur and natural processes would make the patient recover.
After a crisis, a relapse might follow, another deciding crisis. According to this doctrine, crises tend to occur on critical days, which were supposed to be a fixed time after the contraction of a disease. If a crisis occurred on a day far from a critical day, a relapse might be expected. Galen believed that this idea originated with Hippocrates, though it is possible that it predated him. Hippocratic medicine was passive; the therapeutic approach was based on "the healing power of nature". According to this doctrine, the body contains within itself the power to re-balance the four humours and heal itself. Hippocratic therapy focused on easing this natural process. To this end, Hippocrates believed "rest and immobilization
Biology is the natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms and evolution. Despite the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, evolution as the engine that propels the creation and extinction of species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis. Sub-disciplines of biology are defined by the research methods employed and the kind of system studied: theoretical biology uses mathematical methods to formulate quantitative models while experimental biology performs empirical experiments to test the validity of proposed theories and understand the mechanisms underlying life and how it appeared and evolved from non-living matter about 4 billion years ago through a gradual increase in the complexity of the system.
See branches of biology. The term biology is derived from the Greek word βίος, bios, "life" and the suffix -λογία, -logia, "study of." The Latin-language form of the term first appeared in 1736 when Swedish scientist Carl Linnaeus used biologi in his Bibliotheca botanica. It was used again in 1766 in a work entitled Philosophiae naturalis sive physicae: tomus III, continens geologian, phytologian generalis, by Michael Christoph Hanov, a disciple of Christian Wolff; the first German use, was in a 1771 translation of Linnaeus' work. In 1797, Theodor Georg August Roose used the term in the preface of a book, Grundzüge der Lehre van der Lebenskraft. Karl Friedrich Burdach used the term in 1800 in a more restricted sense of the study of human beings from a morphological and psychological perspective; the term came into its modern usage with the six-volume treatise Biologie, oder Philosophie der lebenden Natur by Gottfried Reinhold Treviranus, who announced: The objects of our research will be the different forms and manifestations of life, the conditions and laws under which these phenomena occur, the causes through which they have been effected.
The science that concerns itself with these objects we will indicate by the name biology or the doctrine of life. Although modern biology is a recent development, sciences related to and included within it have been studied since ancient times. Natural philosophy was studied as early as the ancient civilizations of Mesopotamia, the Indian subcontinent, China. However, the origins of modern biology and its approach to the study of nature are most traced back to ancient Greece. While the formal study of medicine dates back to Hippocrates, it was Aristotle who contributed most extensively to the development of biology. Important are his History of Animals and other works where he showed naturalist leanings, more empirical works that focused on biological causation and the diversity of life. Aristotle's successor at the Lyceum, wrote a series of books on botany that survived as the most important contribution of antiquity to the plant sciences into the Middle Ages. Scholars of the medieval Islamic world who wrote on biology included al-Jahiz, Al-Dīnawarī, who wrote on botany, Rhazes who wrote on anatomy and physiology.
Medicine was well studied by Islamic scholars working in Greek philosopher traditions, while natural history drew on Aristotelian thought in upholding a fixed hierarchy of life. Biology began to develop and grow with Anton van Leeuwenhoek's dramatic improvement of the microscope, it was that scholars discovered spermatozoa, bacteria and the diversity of microscopic life. Investigations by Jan Swammerdam led to new interest in entomology and helped to develop the basic techniques of microscopic dissection and staining. Advances in microscopy had a profound impact on biological thinking. In the early 19th century, a number of biologists pointed to the central importance of the cell. In 1838, Schleiden and Schwann began promoting the now universal ideas that the basic unit of organisms is the cell and that individual cells have all the characteristics of life, although they opposed the idea that all cells come from the division of other cells. Thanks to the work of Robert Remak and Rudolf Virchow, however, by the 1860s most biologists accepted all three tenets of what came to be known as cell theory.
Meanwhile and classification became the focus of natural historians. Carl Linnaeus published a basic taxonomy for the natural world in 1735, in the 1750s introduced scientific names for all his species. Georges-Louis Leclerc, Comte de Buffon, treated species as artificial categories and living forms as malleable—even suggesting the possibility of common descent. Although he was opposed to evolution, Buffon is a key figure in the history of evolutionary thought. Serious evolutionary thinking originated with the works of Jean-Baptiste Lamarck, the first to present a coherent theory of evolution, he posited that evolution was the result of environmental stress on properties of animals, meaning that the more and rigorously an organ was used, the more complex and efficient it would become, thus adapting the animal to its environment. Lamarck believed that these acquired traits could be passed on to the animal's offspring, who would
Animal psychopathology is the study of mental or behavioral disorders in animals. There has been an anthropocentric tendency to emphasize the study of animal psychopathologies as models for human mental illnesses, but animal psychopathologies can, from an evolutionary point of view, be more properly regarded as non-adaptive behaviors due to some sort of a cognitive disability, emotional impairment or distress. This article provides a non-exhaustive list of animal psychopathologies. Animals in the wild appear to be free from eating disorders although their body composition fluctuates depending on seasonal and reproductive cycles. However, domesticated animals including farm and pet animals are prone to disorders. Evolutionary fitness drives feeding behavior in wild animals; the expectation is that farm animals display this behavior, but questions arise if the same principles apply to laboratory and pet animals. Activity anorexia is a condition where rats begin to exercise excessively while cutting down on their food intake, similar to human anorexia nervosa or hypergymnasia.
When given free access to food and an exercise wheel, rats develop a balanced routine between exercise and food intake, which turns them into fit rats. However, if food intake is restricted and wheel access is unrestricted, rats begin to exercise more and eat less, resulting in excessive weight loss and death; the running cycles shift. In other conditions, AA does not develop. Unrestricted food access and restricted wheel access will not cause any significant change in either feeding or exercise routine. If rats are restricted both in food intake and wheel access, they will adjust accordingly. In fact, if rats are first trained to the feeding schedule and given unrestricted access to a running wheel, they will not develop AA behavior. Results support the notion that the running interferes with adaptation to the new feeding schedule and is associated with the reward system in the brain. One theory is that running simulates a natural behavior in wild rats. Laboratory rats therefore run more in response to food shortages.
The effect of semi-starvation on activity has been studied in primates. Rhesus macaque males become hyperactive in response to long-term chronic food restriction. Thin Sow Syndrome is a behavior observed in stalled sows, similar to AA where some sows after early pregnancy are active, eat little, waste away, resulting often in death, they suffer from emaciation, hypothermia, a depraved appetite and hyperactivity. The syndrome may be related to social and environmental stressors. Stress in stalled sows is perceived as the consequence of the restraint of animals that happens in intensive production units; the sows that suffer the most restraining conditions are those lactating or pregnant as they have little room to move around because they are kept in barred gestation crates or tethered for the 16 weeks of pregnancy which prevents natural and social behaviors. However, increased movement and freedom is stressful for adult sows, the case after weaning; when placed into groups they fight vigorously, with one dominant sow emerging.
It is likely that two subordinate sows make up part of the group who avoid competitive feeding situations and are bullied by the dominant sow. Affected sows have poor appetite but show pica, excessive water intake and are anemic. Studies on the effects of overcrowding were conducted in the 1940s by placing pregnant Norway rats in a room with plenty of water and food and observing the population growth; the population did not grow thereafter. Though there was plenty of water and food, the rats stopped eating and reproducing. Similar effects have been observed in dense populations of beetles; when overcrowding occurs, female beetles destroy their eggs and turn cannibalistic, eating each other. Male beetles lose interest in the females and although there is plenty of water and food, there is no population growth. Similar effects have been observed in overcrowded situations in jack deer. Pica has so far been poorly documented. In non-human animals in the laboratory it has been examined through the ingestion of kaolin by rats.
Rats were induced to intake kaolin by administering various emetic stimuli such as copper sulfate, apomorphine and motion. Rats are unable to vomit when they ingest a substance, harmful thus pica in rats is analogous to vomiting in other species. In some animals pica seems to be an adaptive trait but in others it seems to be a true psychopathology like in the case of some chickens. Chickens can display a type of pica, they increase their non-nutritive pecking, such as pecking structural features of their environment like wood or wire on fences or the feathers of other birds. It is a typical response that occurs when feeding is restricted or is withdrawn; some of the non-nutritive pecking may be due to a redirection of foraging related behavior. Another animal that has displayed a more complex pica example are cattle. Cattle eat bones. However, in some cases they persist on eating bones after their phosphorus levels have stabilized and they are getting adequate doses of phosphorus in their diet.
In this case evidence supports both
Karl Theodor Jaspers was a German-Swiss psychiatrist and philosopher who had a strong influence on modern theology and philosophy. After being trained in and practicing psychiatry, Jaspers turned to philosophical inquiry and attempted to discover an innovative philosophical system, he was viewed as a major exponent of existentialism in Germany, though he did not accept the label. Jaspers was born in Oldenburg in 1883 to a mother from a local farming community, a jurist father, he showed an early interest in philosophy, but his father's experience with the legal system undoubtedly influenced his decision to study law at University of Heidelberg. It soon became clear that Jaspers did not enjoy law, he switched to studying medicine in 1902 with a thesis about criminology. In 1910 he married the sister of his close friends Gustav Mayer and Ernst Mayer. Jaspers earned his medical doctorate from University of Heidelberg medical school in 1908 and began work at a psychiatric hospital in Heidelberg under Franz Nissl, successor of Emil Kraepelin and Karl Bonhoeffer, Karl Wilmans.
Jaspers became dissatisfied with the way the medical community of the time approached the study of mental illness and gave himself the task of improving the psychiatric approach. In 1913 Jaspers habilitated at the philosophical faculty of the Heidelberg University and gained there in 1914 a post as a psychology teacher; the post became a permanent philosophical one, Jaspers never returned to clinical practice. During this time Jaspers was a close friend of the Weber family. In 1921, at the age of 38, Jaspers turned from psychology to philosophy, expanding on themes he had developed in his psychiatric works, he became a philosopher, in Europe. After the Nazi seizure of power in 1933, Jaspers was considered to have a "Jewish taint" due to his Jewish wife, was forced to retire from teaching in 1937. In 1938 he fell under a publication ban as well. Many of his long-time friends stood by him, he was able to continue his studies and research without being isolated, but he and his wife were under constant threat of removal to a concentration camp until 30 March 1945, when Heidelberg was liberated by American troops.
In 1948 Jaspers moved to the University of Basel in Switzerland. He remained prominent in the philosophical community and became a naturalized citizen of Switzerland living in Basel until his death on his wife's 90th birthday in 1969. Jaspers' dissatisfaction with the popular understanding of mental illness led him to question both the diagnostic criteria and the methods of clinical psychiatry, he published a paper in 1910 in which he addressed the problem of whether paranoia was an aspect of personality or the result of biological changes. Although it did not broach new ideas, this article introduced a rather unusual method of study, at least according to the norms prevalent. Not unlike Freud, Jaspers studied patients in detail, giving biographical information about the patients as well as notes on how the patients themselves felt about their symptoms; this has become known as the biographical method and now forms a mainstay of psychiatric and above all psychotherapeutic practice. Jaspers set down his views on mental illness in a book which he published in 1913, General Psychopathology.
This work has become a classic in the psychiatric literature and many modern diagnostic criteria stem from ideas found within it. One of Jaspers' central tenets was that psychiatrists should diagnose symptoms of mental illness by their form rather than by their content. For example, in diagnosing a hallucination, it is more important to note that a person experiences visual phenomena when no sensory stimuli account for them, than to note what the patient sees. What the patient sees is the "content", but the discrepancy between visual perception and objective reality is the "form". Jaspers thought, he argued that clinicians should not consider a belief delusional based on the content of the belief, but only based on the way in which a patient holds such a belief. Jaspers distinguished between primary and secondary delusions, he defined primary delusions as autochthonous, meaning that they arise without apparent cause, appearing incomprehensible in terms of a normal mental process. Secondary delusions, on the other hand, he defined as those influenced by the person's background, current situation or mental state.
Jaspers considered primary delusions to be "un-understandable," since he believed no coherent reasoning process existed behind their formation. This view has caused some controversy, the likes of R. D. Laing and Richard Bentall have criticised it, stressing that this stance can lead therapists into the complacency of assuming that because they do not understand a patient, the patient is deluded and further investigation on the part of the therapist will have no effect. For instance Huub Engels argues that schizophrenic disordered speech may be understandable, just as Emil Kraepelin's dream speech is understandable. Most commentators associate Jaspers with the philosophy of existentialism, in part because he draws upon the existentialist roots of Nietzsche and Kierkegaard, in part because the theme of individual freedom permeates his work. In Philosophy, Jaspers gave his view of the history of philosophy and i
Plato was an Athenian philosopher during the Classical period in Ancient Greece, founder of the Platonist school of thought, the Academy, the first institution of higher learning in the Western world. He is considered the pivotal figure in the history of Ancient Greek and Western philosophy, along with his teacher and his most famous student, Aristotle. Plato has often been cited as one of the founders of Western religion and spirituality; the so-called Neoplatonism of philosophers like Plotinus and Porphyry influenced Saint Augustine and thus Christianity. Alfred North Whitehead once noted: "the safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato."Plato was the innovator of the written dialogue and dialectic forms in philosophy. Plato appears to have been the founder of Western political philosophy, his most famous contribution bears his name, the doctrine of the Forms known by pure reason to provide a realist solution to the problem of universals.
He is the namesake of Platonic love and the Platonic solids. His own most decisive philosophical influences are thought to have been along with Socrates, the pre-Socratics Pythagoras and Parmenides, although few of his predecessors' works remain extant and much of what we know about these figures today derives from Plato himself. Unlike the work of nearly all of his contemporaries, Plato's entire oeuvre is believed to have survived intact for over 2,400 years. Although their popularity has fluctuated over the years, the works of Plato have never been without readers since the time they were written. Due to a lack of surviving accounts, little is known about education. Plato belonged to an influential family. According to a disputed tradition, reported by doxographer Diogenes Laërtius, Plato's father Ariston traced his descent from the king of Athens and the king of Messenia, Melanthus. Plato's mother was Perictione, whose family boasted of a relationship with the famous Athenian lawmaker and lyric poet Solon, one of the seven sages, who repealed the laws of Draco.
Perictione was sister of Charmides and niece of Critias, both prominent figures of the Thirty Tyrants, known as the Thirty, the brief oligarchic regime, which followed on the collapse of Athens at the end of the Peloponnesian War. According to some accounts, Ariston tried to force his attentions on Perictione, but failed in his purpose; the exact time and place of Plato's birth are unknown. Based on ancient sources, most modern scholars believe that he was born in Athens or Aegina between 429 and 423 BC, not long after the start of the Peloponnesian War; the traditional date of Plato's birth during the 87th or 88th Olympiad, 428 or 427 BC, is based on a dubious interpretation of Diogenes Laërtius, who says, "When was gone, joined Cratylus the Heracleitean and Hermogenes, who philosophized in the manner of Parmenides. At twenty-eight, Hermodorus says, went to Euclides in Megara." However, as Debra Nails argues, the text does not state that Plato left for Megara after joining Cratylus and Hermogenes.
In his Seventh Letter, Plato notes that his coming of age coincided with the taking of power by the Thirty, remarking, "But a youth under the age of twenty made himself a laughingstock if he attempted to enter the political arena." Thus, Nails dates Plato's birth to 424/423. According to Neanthes, Plato was six years younger than Isocrates, therefore was born the same year the prominent Athenian statesman Pericles died. Jonathan Barnes regards 428 BC as the year of Plato's birth; the grammarian Apollodorus of Athens in his Chronicles argues that Plato was born in the 88th Olympiad. Both the Suda and Sir Thomas Browne claimed he was born during the 88th Olympiad. Another legend related that, when Plato was an infant, bees settled on his lips while he was sleeping: an augury of the sweetness of style in which he would discourse about philosophy. Besides Plato himself and Perictione had three other children; the brothers Adeimantus and Glaucon are mentioned in the Republic as sons of Ariston, brothers of Plato, though some have argued they were uncles.
In a scenario in the Memorabilia, Xenophon confused the issue by presenting a Glaucon much younger than Plato. Ariston appears to have died in Plato's childhood, although the precise dating of his death is difficult. Perictione married Pyrilampes, her mother's brother, who had served many times as an ambassador to the Persian court and was a friend of Pericles, the leader of the democratic faction in Athens. Pyrilampes had a son from a previous marriage, famous for his beauty. Perictione gave birth to Pyrilampes' second son, the half-brother of Plato, who appears in Parmenides. In contrast to his reticence about himself, Plato introduced his distinguished relatives into his dialogues, or referred to them with some precision. In addition to Adeimantus and Glaucon in the Republic, Charmides has a dialogue named after him; these and other references suggest a considerable amount of family pride and enable us to reconstruct Plato's family tree. According to Burnet, "the opening scene of the Ch