If it is not the mind, vital or physical which take birth again but only the psychic being, then the vital or mental progress made before is of no value in another life?

It happens only to the extent the progress of these parts has brought them close to the psychic, that is, to the extent the progress lies in putting all the parts of the being successively under the psychic influence. For all that is under the psychic influence and identified with the psychic continues, and it is that alone which continues. But if the psychic is made the centre of one's life and consciousness, and if the whole being is organised around it, the whole being passes under the psychic influence, becomes united with it, and can continue -if it is necessary for it to continue. Indeed, if the physical body could be given the same movement -the same movements of progress and the same capacity to ascend that the psychic being has well, it wouldn't be necessary for it to decompose. But that indeed is the difficulty.
  And only that which is in contact with the psychic lasts, and only what can last can remember, for the rest disappears, is again dissolved into small pieces and utilised elsewhere -as the body is dissolved again to dust and used elsewhere. It goes back to the earth, plants use the soil, men eat the plants. It is in this way that it goes on. And then it returns to the earth and begins again. That's the way Nature progresses. In order to progress she makes a heap of forms, then, when that seems no longer important or necessary to her, she demolishes them, takes up all the elements again, chemical or other, and reconstitutes something else, and so it goes on changing all the time, cpming and going. And she finds that very good, for she sees very far, her work extends over centuries, and a small human life is nothing, just a breath in eternity. So she takes up, shapes; she takes a certain time, it's fun for her, she finds it very good; and then, when it is no longer so good, she demolishes it -she takes up, mixes every- thing, begins another form, makes something else. And so perhaps with this process which is evidently very slow, finally the whole of matter progresses. It is possible - always in this way, intermingling, breaking up, remixing, breaking up again. Essentially, it is as though one made a heap of small objects and then destroyed them, remade something from the dust, remade other toys, and again broke them, and remade others out of that. Each time one adds something so that it mixes well. And then, one day, perhaps all that will produce something. In any case, she is in no hurry. And when we are in a hurry, she says: "Why are you in such a haste? It is sure to happen one day. You don't need to worry, it will surely come. Wait quietly."
Then we tell her: "But it is not I who am waiting!" - " Ah! that's because you call 'I' that thing which comes and goes away. If you were to call consciousness -the one, eternal and divine consciousness- if you were to call that 'I', then you would see everything, you would be present at everything. Nobody prevents you from doing it! It is only because you identify yourself with this (indicating the body). You have only to stop identifying yourself with that."

The Mother