Rene Descartes began attending La Fleche at the age of 10.  La Fleche was regarded as one of the most advanced and prestigious institutions of its time, teaching science and mathematics alongside the traditional subjects of literature, languages, philosophy, and theology.  The young Rene was schooled according to Aristotelian views of a geocentric universe and the hierarchy of vegetative, sensitive, and rational souls.  He mastered virtually all that could be taught at La Fleche, and was regarded as an extraordinary student.  He even managed to convince his teachers that he did his best thinking in bed, thus allowing him a couple more hours of sleep than his fellow students.  At the age of 16, Descartes graduated from La Fleche as the top student. 

Descartes lived an eventful life, finding himself in places as Paris and St. Germain.  Rene Descarted died in 1650. 

Descartes was a rationalist, and argued that the only way to enlightenment and discovery was to doubt everything, to question its properties, its mechanisms, etc.

In observing something as mundane as a fly buzzing around his room, Descartes developed an interesting theory.  He found a way of integrating geometry with algebra in defining shapes with numbers.  He used a mathematical approach to gaining knowledge, keeping in mind the principles of geometry. 

Using his mathematical and mechanistic approach, he came up with a unique theory of mind and body.  He analyzed such physiological functions as the circulation of blood, growth of the body, respiration, sleeping and waking, sensation, memory, and movement.  He expressed interest in the brain's structure, explaining it as a system of tubes and valves that allowed the flow of "animal spirits" (now known as cerebrospinal fluid) throughout the brain.  He explained the functions of the brain as being a product of the "animal spirits'" movement. 

In this way, Descartes gave way to analytical, rational thought in psychology, and also set the foundations for today's neuroscientists.   

Rene Descartes' famous quote, "I think therefore I am" best describes his feelings on the topic of the mind and emotions.  Because he believed that nothing aside from doubt was certain, he even doubted his own senses.  He viewed the intellectual functions of the mind as innate and fundamental, more so than sensory data.  On this level, he is deemed a nativist, believing in innate abilities existing prior to experience.  He stressed the importance of the interaction of mind and body, saying that without a mind, the body would be comparable to a robot, functioning without purpose.  He also notes that in the reverse context, the mind without a body would be unable to enrich its innate abilities or gather sensory experience to further knowledge. 

This body-mind interaction fueled Descartes' theory of "passions" or emotions, describing the "animal spirits'" flow to induce the sensation of these "passions" such as anger, pain, sadness, and happiness, and the body and soul's conscious decision to act upon them.  He noted that the expression of emotion involved a conflict between the soul and body.