The concept of the three modes of material nature is an integral part of the Vaishnava world view and impacts all aspects of Vaishnava thought. According to this concept, material existence is understood in terms of three essential characteristics: sattva (goodness, virtue), rajas (passion, energy), and tamas (ignorance, inertia).

The word "mode" is a loose translation of the Sanskrit word guna, which literally means "thread" or "rope" (implying that goodness, passion, and ignorance are the ropes that bind individuals to the material world). These constituent qualities underlie everything we see, hear, taste, touch, and smell. The entire world, in fact, is made up of various permutations of these qualities, and like the primary colors, red, blue, and yellow, the gunas can be mixed in unlimited ways, producing uncountable variations.

Sattva is associated with virtues and qualities such as wisdom, joy, and altruism; rajas with ambition, greed, frustration, and anger; and tamas with idleness, sloth, and delusion. In the Varnashrama system (the four material and spiritual sections of human society), for example brahmanas are considered to be in the mode of goodness, kshatriyas in the mode of passion, vaishyas in passion and ignorance combined, and shudras in ignorance.

The three modes are often described as clarifying, confusing, and obscuring, or as pacifying, impelling, and impeding, respectively. In the Vaishnava tradition each mode is associated with a principle deity: Vishnu, the Supreme Godhead, who maintains the cosmic manifestation, is the master of the mode of goodness; Brahma, the creator demigod, predominates over passion; and Shiva, the destroyer, presides over ignorance.

In a given person's life, a particular mode predominates, and this conditions the way he or she behaves. Understanding how one is conditioned by the modes, and how the modes are interacting with the consciousness, helps an individual achieve stability and happiness. Still, one should aspire to become detached from all three modes, even from goodness. Although goodness embodies finer material qualities, such qualities are still material and can serve as "the last infirmity of a noble mind," as indologist A.L. Basham has said, "causing the soul to cling to wisdom and joy as opposed to God consciousness proper."

The first systematic analysis of the modes occurs in the Bhagavad-gita, which devotes to this subject 100 of its 700 verses. According to the Gita, God, as the creator of the modes, is naturally above them (7.13), but the ordinary soul is not (14.5). The Gita's fourteenth chapter outlines the general characteristics of the modes, stressing the importance of understanding and thus rising beyond them. The seventeenth chapter analyzes the workings of the modes in the areas of worship, sacrifices, and austerities, in the food one eats, and even in the way one distributes gifts. Essentially, the Gita brings into focus the subtleties of the three modes and helps us understand distinct personality types resulting from these modes.