As per Ayurveda, the modes of nature have been divided into three categories, Sattva, Rajas and Tama. They are the modes which act mainly on the physical and the mental behavior of a person and hence, have a nice as well as a predominant effect on the nature of a person.
The first and foremost of them is Sattva Guna or the mode of goodness. This is the most powerful mode for the mind and is related directly with a controlled mind. When one comes in the mode of goodness, he can experience that his senses have been illuminated by knowledge.
The scripture Bhagwad Gita illustrates the effect of mode of goodness on various activities.
Bg 14.6 — O sinless one, the mode of goodness, being purer than the others, is illuminating, and it frees one from all sinful reactions. Those situated in that mode become conditioned by a sense of happiness and knowledge.
Bg 14.9 — O son of Bharata, the mode of goodness conditions one to happiness.
Bg 14.11 — The manifestation of the mode of goodness can be experienced when all the gates of the body are illuminated by knowledge.
Bg 14.14 — When one dies in the mode of goodness, he attains to the pure higher planets of the great sages.
Bg 14.17 — From the mode of goodness, real knowledge develops.
Bg 14.18 — Those situated in the mode of goodness gradually go upward to the higher planets
This is a brief description of a personality situated in the mode of goodness. Mode of goodness is predominated by the sweet taste and the food which is juicy. Foods dear to those in the mode of goodness increase the duration of life, purify one’s existence and give strength, health, happiness and satisfaction. Such foods are juicy, fatty, wholesome, and pleasing to the heart (Bhagwad Gita 17.8).
When a person is in the mode of goodness, he is able to make discrimination between what is good and what is bad. He is very clean, tolerant and has control over his mind. Such a person never commits Pragyaparadh, the cause of all mental miseries in the science of Ayurveda. He never eats what is forbidden and what is not good for his health. He knows what the seasonal regime is and what is to be taken and what is not to be taken. Since his senses are illuminated by knowledge he has a clear mindset and hence, is very less prone to mental illness.
He may come to the stage of false arrogance of knowledge and hence, may have to suffer the result of the same.