Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 2
The weakness in yourself of which you speak is there, as the persistency of these movements [of despondency] shows, but it is not in the heart – your heart is all right – but in the lower vital nature. All your weaknesses are there; the rest of your being is quite strong enough for the spiritual life. But this inadequacy of the lower vital is not peculiar to you, it is present in almost every human being. This tendency to irrational sadness and despondency and these imaginations, fears and perverse reasonings – always repeating, if you will take careful notice, the same movements, ideas and feelings and even the same language and phrases like a machine – is a characteristic working of the lower vital nature. The only way to get rid of it is to meet it with a fixed resolution of the higher vital and the mind and psychic being to combat, reject and master it. As you were determined to master the sex impulse and the desire of the palate, so you 
must determine to master this “irrational knot” of despondency in the lower vital nature. If you indulge it and regard it as a natural part of yourself with good causes for existence or if you busy yourself finding this or that justification for it when it comes, there is no reason why it should let go its unpleasant grip upon you. Be firm and courageous here, as you have learnt to be with other movements of your lower vital; you will then, I think, find less difficulty in your meditation and your general sadhana.