Other common states that we expcrience are fear and anziety During these states, far more than the normal amount ofacid required is excreted into the intestinal tracts whereby the membranc is attacked resulting in ulcers
Prolonged states of nervous tension are known to impair the autonomic nervous system in such a way that it influences negatively peristasis which impairs the digestive functions and elimination. This results in constipation and self-poisoning, thus adversely sffecting the physical, emotional and mental health of the individual.
It can be seen why the Buddha stessed the prectice of vitue as a prerequisite for meditation. The prectice of meditation is impossible when the physical body, emotions and mind of the individual are impaired. One who has practised virtue can successfully pursue miditation, discard the hindrances and can comtemplate on reality and finally acquire liberation. These three major objectives can be attained whithin in the Four jhānas
Just as in science accomplishment of a goal is gradual and methodical, so also the attainment of the Buddhist goal in meditation is gradual and hierachical and is closely linked whit the physical states of the body.
The adoption of a steady posture, the dwelling of the mind steadfastly without distraction and having intense concentration are the prime requirements for meditation. The Buddha praised highly the method of Producing serenity though mindfulness of breathing by way of which he himself attained enlightenment.
Modern researchers have found that subjects during meditation decreased their respiration rate, their consumption of oxygen decreased by about 20% and a reduction of CO2 output was noticed.
Other demonstrated physiological effects are the reduction of the rate of metabolism, the decrease in lactic acid in blood with concomitant rise in pH and a decrease in the Galvanic skin response.