Before we begin our review of the lines of Karma related to the mental being, it is essential to gain a clear perspective on the various aspects that make up our mental functioning. There is the practical mind that involves itself with the physical and vital levels of existence and works to manage and utilize them to best advantage; there is also a higher mind of thought and concept, as well as an aesthetic and an emotional aspect that weave the complex fabric that we consider to be mental functioning.
Sri Aurobindo explains: “The mental energy divides itself and runs in many directions, has an ascending scale of the levels of its action, a great variety and combination of its dynamic aims and purposes. There are many strands of its weaving and it follows each along its own line and combines manifoldly he threads of one with the threads of another. There is in it an energy of thought that puts itself out for a return and a constant increase of knowledge, an energy of will that casts itself forth for a return and increase of conscious mastery, fulfilment of the being, execution of will in action, an energy of conscious aesthesis that feels out for a return and an increase of the creation and enjoyment of beauty, an energy of emotion that demands in its action a return and a constant increase of the enjoyment and satisfaction of the emotional power of the being. All these energies act in a way for themselves and yet depend upon and are inextricably accompanied and mingled with each other. At the same time mind has descended into matter and has to act in and through this world of the vital and physical energy and to consent to and make something of the lines of the vital and physical Karma.”
It is not simply the complexity of these different energies and levels of action that we have to contend with; we also have to take into account the varying concentration and intensity of the energy put forth within each of these lines. A weak force will soon be deflected, drowned out or watered down by the myriad other active forces around it and with which it needs to contend.
Sri Aurobindo, Rebirth and Karma, Section II, Chapter 15, Mind Nature and Law of Karma, pp. 127-128, http://www.lotuspress.com/item.php?item=990117