It is the energy / force of balance and equilibrium and translates in quality as good and harmony and happiness and light.
It is force of motion, vibration and translates in quality as struggle and effort, passion and action. It is fast moving and unrythmic. All pressure, tension, stress, worry, impulsive behavior pattern are its creation.
All energy in its grossest, densest and heaviest form is tamasic energy. A dark heavy cloud is tamasic energy. It is force of ignorance and inertia and translates in quality as obscurity and incapacity and inaction. It makes the body and mind feel lazy, heavy , sleepy and dull. Ordinarily used for psychological self –analysis, these distinctions are valid in physical Nature as well. Each object and every life-form in the universe contains them and their characteristic properties are the result of the interaction of these three distinct qualitative forces. Every form, whether animate or inanimate is a constantly maintained balance of natural forces in motion and is subject to an unending stream of helpful disturbing or disintegrating contacts from other combination of forces that surround it. Our own mind is nothing else such a formative combination and balance. In the reception the environmental contacts and the reaction to them, the three modes determine the temper of the recipient and the character of the response.
Life dominated by Tamas
Inert and inept, a Tamasic man suffers the environmental influences without any responsive reaction, any motion of self-defense or any capacity of assimilation and adjustment. The stigmata of Tamas are blindness and unconsciousness and incapacity and unintelligence, sloth and indolence and inactivity and mechanical routine and the mind's torpor and body's inertia and the soul's slumber. Its effect , if uncorrected by other elements, can be nothing but disintegration of the form or the poise of the nature without any new creation or new equilibrium or force of kinetic progress. At the heart of this inert impotence is the principle of ignorance and an inability or slothful unwillingness to comprehend, seize and manage the simulating or assailing contact, the suggestion of environmental forces and their urge towards fresh experience .
Life dominated by Rajas
On the other hand, the recipient of the Nature's influences, touched and stimulated, asailed by Her forces, may react to the pressure or against it. She allows, encourages, impels him to strive, to resist, to attempt, to dominate, to assert his will to fight and create and conquer. This is the mode of the Rajas, the way of passion and action and the thirst of desire. Struggle and change and new creation, victory and defeat and joy and suffering and hope and disappointment are its children and build the many colored house of life in which it takes its pleasure. But its knowledge is an imperfect or a false knowledge and brings with it ignorant effort, error and constant maladjustments, pain of attachment, disappointed desire, grief of