True knowledge means understanding the distinction between matter and spirit, the temporary and eternal, the body and the soul. The Bhagavad-gita (4.34-39) teaches that one should approach a guru to understand this knowledge, and (7.2) states that knowing the Supreme is perfect knowledge. The Bhagavad-gita (13.2-3) explains the difference between the body and the soul. Material knowledge deals with temporary phenomena, while spiritual knowledge concerns eternal truth. The Science of Self-Realization (Chapter 1) elaborates that the highest knowledge is knowing the Supreme Personality.

Consciousness is the symptom of the soul. The Bhagavad-gita (2.62-66) teaches how to control the mind and senses, and (6.5-6) explains that the mind can be one's friend or enemy. The Bhagavad-gita (8.5-6) describes how consciousness at death determines one's future destination. The quality of consciousness determines one's experience and future destination. Purifying consciousness through devotional service is the goal of spiritual practice. Perfect Questions Perfect Answers (Chapters 1 and 5) further clarifies that pure consciousness is Krishna consciousness.