Taken from “The Yoga of Herbs – An Ayurvedic Guide to Herbal Medicine” written by: Dr. David Frawley and Dr. Vasant Lad
In order to understand the Ayurvedic approach to herbs, one must understand the basic system of Ayurveda, which is a complete healing science, including the physical, psychological and spiritual aspects of life.
The ancient seers of India envisioned two fundamental principles behind existence: Purusha, the Primal Spirit, the principle of sentience of consciousness; and the Prakruti, or Great Nature, the principle of creativity. The union of these two, Spirit and Matter, produces all things.
Yet these two are also one, the primordial Two-in-One, Consciousness and its creative, executive force, Shiva-Shakti. Within all things is essence, individuality, consciousness – the Purusha. Within all things is also the power of manifestation, the capacity for creative enfoldment – Prakruti.
From these two great forces in their initial coming together is born Cosmic Intelligence, Mahat, which contains the seeds of all manifestation. Inherent in the Mahat are all laws of nature.
The Cosmic Intelligence also exists in the human being as the intelligence in the individual. As such it is called Buddhi, the means of awakening, developing fully which one becomes enlightened, a Buddha. Buddhi is our capacity for perception, our ability to discern the real from the unreal. But this intelligence, in its evolution into material forms, may give rise to the ego, the sense of separate self, or Ahamkara. It is the principle of division as it is only our sense of a separate ego that divides us from the unity of life.
In turn, the ego gives rise to the conditioned mind or conditioned consciousness called Manas, which, as our sense of self-consciousness, creates a protective thought-field around itself in which we become bound.
Finally, this links us up with the collective unconscious called Chitta, the storehouse of thoughts of all limited mentalities. Through the Chitta we remain under the influence of latencies, compulsions and drives of the earlier stages of evolution, going all the way back to the animal realm and before.
Ayurveda aims at a life in harmony with Cosmic Intelligence, whereby our own intelligence is perfected, so that through it we can return to unity with nature; and through nature our true self and spirit, the Purusha. This is the spiritual background of Ayurveda, which is the same as that of Yoga, and the basis of Ayurvedic psychology.
This requires the awakening of intelligence wherein we go beyond the rule of the ego. The ego is the basis for all deviation from nature. Health is natural, Prakruti. Disease is artificial, Vikruti. Hence, most diseases, except those natural to the course of time, are from the psychological imbalance born of unnecessary self-consciousness.