People for the most part look after their bodies without looking after their minds. This is why, even though they may experience physical pleasure to some extent, they don’t have much mental pleasure to speak of. The major factor, the mind, rarely feels pleasure even when there’s pleasure in the minor factor, the body. The body is a minor factor when compared to the mind. The mind is the major factor in each person, but instead of taking good care of this major factor, this basis for the body, we hardly ever look after it at all.
Venerable Ăcariya Mahà Boowa Ňàõasampanno, A Life of Inner Quality: A Comprehensive Guide to Buddhist Practice
Man's mind influences his body profoundly. The mind has just as much potential to be a medication as it has to be a poison. When the mind is vicious, it can kill a being but when it is steady and diligent it can benefit others. When the mind is concentrated on right thoughts, and supported by right effort and understanding, the effect it produces is immense. A mind with pure and wholesome thoughts leads to healthy relaxed living.
Venerable K. Sri Dhammananda, Problems and Responsibilities