The last two he described as the "senium", a period of mental and physical decay, and that the final phase was when "the scene of mortal existence closes after a great length of time that very fortunately, few of the human species arrive at, where the mind is reduced to the imbecility of the first epoch of infancy". In 550 BC, the Athenian statesman and poet Solon argued that the terms of a mans will might be invalidated if he exhibited loss of judgement due to advanced age. Chinese medical texts made allusions to the condition as well, and the characters for "dementia" translate literally to "foolish old person".Athenian philosophers Aristotle and Plato discussed the mental decline that can come with old age and predicted that this affects everyone who becomes old and nothing can be done to stop this decline from taking place. Plato specifically talked about how the elderly should not be in positions that require responsibility because, "There is not much acumen of the mind that once carried them in their youth, those characteristics one would call judgement, imagination, power of reasoning, and memory. They see them gradually blunted by deterioration and can hardly fulfill their function. "For comparison, the Roman statesman Cicero held a view much more in line with modern-day medical wisdom that loss of mental function was not inevitable in the elderly and "affected only those old men who were weak-willed". He spoke of how those who remained mentally active and eager to learn new things could stave off dementia.
Terminology
Dementia in the elderly was once called senile dementia or senility, and viewed as a normal and somewhat inevitable aspect of aging.By 1913–20 the term dementia praecox was introduced to suggest the development of senile-type dementia at a younger age. Eventually the two terms fused, so that until 1952 physicians used the terms dementia praecox (precocious dementia) and schizophrenia interchangeably. Since then, science has determined that dementia and schizophrenia are two different disorders, though they share some similarities. The term precocious dementia for a mental illness suggested that a type of mental illness like schizophrenia (including paranoia and decreased cognitive capacity) could be expected to arrive normally in all persons with greater age (see paraphrenia). After about 1920, the beginning use of dementia for what is now understood as schizophrenia and senile dementia helped limit the words meaning to "permanent, irreversible mental deterioration". This began the change to the later use of the term. In recent studies, researchers have seen a connection between those diagnosed with schizophrenia and patients who are diagnosed with dementia, finding a positive correlation between the two diseases.The view that dementia must always be the result of a particular disease process led for a time to the proposed diagnosis of "senile dementia of the Alzheimers type" (SDAT) in persons over the age of 65, with "Alzheimers disease" diagnosed in persons younger than 65 who had the same pathology.