Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 3
As to what has happened in your sadhana, it is that you have allowed yourself to fall into a groove of the physical mind and 
of the external vital nature and got fixed in a persistent or constantly recurrent repetition of the ideas and feelings which they present to you – feelings of settled disappointment and discouragement and pessimism about yourself and your spiritual future, and ideas – or, if you will allow me to call them so, notions – which come to the support of these feelings and sustain them. The result of this is to shut you up against the contact and spiritual influence and help you were once feeling or beginning to feel from us. It also shuts you up against your own deeper self and sterilises your personal effort. An accident of this kind is common enough in the path of spiritual effort, and the first thing to be done to get rid of its effects is to throw away resolutely the persistent ideas and feelings which keep you in the groove. I do not know whether you can return to the former condition, for it is seldom that one can go back to a point in the past; but it is always possible for you to go forward, recovering the force for propulsion of what you then gained and have certainly still within you assimilated in your inner being. If you want to carry on some part of the Yoga by your active efforts and aspiration, there is no reason why you should not find back that capacity; but the first effort to be made is to reject persistently, fully and tenaciously – not for two or three days, but always, so long as they insist or return – these disabling thoughts and feelings which hamstring all hope and faith in you, not to accept them, not to justify them, not to give them by your acquiescence the right to go on harping on the same note always of discouragement, incapacity and failure. The ideas by which you justify them are, I repeat, notions only of the physical mind, not true things – e.g. the notion that you cannot understand a given idea (intellectually accepting or not accepting is another matter); for it is perfectly certain that your thinking intelligence is quite trained enough to understand anything that is put before it. It is only the physical mind that is limited even in the most intelligent and opens up pits of stupidity or at least larger or smaller spaces of blank non-understanding in the face of unaccustomed ideas or a new line of possible experience or anything else either alien to the mind’s habits or unwelcome to something in the vital parts. I suppose we have all had experience of this incapable element in our nature, and if one fixes oneself in it, it can make even things that would ordinarily be easy for us seem difficult things and things difficult seem impossible. But why should a mind trained to think allow this poorer part of itself to dominate it? So with the other notions. There is nothing anyone else can do in the way of Yoga that you cannot do if you have the fixed will to do it; some things may take a longer time because of past training, habits, mental associations but there is nothing impossible, too difficult, no inherently insuperable obstacle.