The guna are three (tri-guna): tamas, rajas and sattva. The tendency towards inertia comes from tamas guna, the tendency towards activity from rajas guna and the tendency towards balance from sattva guna. The three guna cannot exist without the other. They are like three phases of a wave: tamas being the movement downwards towards the nadir, rajas being the movement upwards towards the crest and sattva being the balance, the point at which there is a pause.
