Read more about Laziness from the works of the Mother and Sri Aurobindo.
What is Laziness?
It is a dangerous illness: laziness. 
In laziness there is an ill-will which refuses to make an effort. It gives rise to excuses and slow in movements which further tends to make any progress. Tiredness shows lack of will for progress. When you feel tired or fatigued that is lack of will for progress. 
Laziness in Instruments
We are made up of different pieces of being which are all gathered together to make us feel alive and act through the person. But there are many of them, and there are in particular concentrations on different planes: just as you have a physical being, you have a vital being, a mental being, a psychic being, and many others with all possible intermediaries. 
Through Mental, the mind tries to control and makes us fall into tamas and unconsciousness which we start acknowledging as relaxing. There is a constant awakening and development of the mind and general awakening of the whole being—which is the opposite of sleep. It is necessary to receive the supreme force and a conscious sleep. 
Through Vital, the body is afraid of trying anything new because of laziness and dullness. Furthermore, it abhors a dull, monotonous, tasteless, worthless life and falls into inertia. The vital which is developed, which has a special capacity, is stronger than the physical inertia and gives an intensity of vibration and life and action that those whose vital being is not developed do not possess. 
Through Physical, physical suffering is to me like a child being beaten, there is no bad will in Matter, everything is inertia and ignorance. There is ignorance in truth, origin, possibility,etc. The physical consciousness gets the true peace and calm in the cells and feels at rest even in full work or in the most concentrated condition and this tendency of inertia goes out of nature. 
There is always a divine Presence in the psychic being. The psychic being is a terrestrial formation. The cells themselves observed something between torpor, drowsiness, numbness and indifference; and that state is mistaken for peace, quietude and acceptance, but it really is a form of tamas
Laziness in Relation to other Attributes/Quality
Depression: It is seen that we always cling on to the old habits and refuse to change or make progress under the pressure of being comfortable at our own pace. However, this often results in unhappiness and leads to serious ailments. During this time, one must refuse to be depressed, and be quiet enough without any worries. By keeping oneself open towards the divine through sincere efforts. 
“Aspire for a positive sattwic opening for strength, for light, for peace and do not worry or repine if the progress is slow at first, nor grudge the time and labour of preparation necessary before there can be a rapid advance in the Yoga.” 
Boredom: It is the dullness and the lack of interest in the work which results in bringing a person to its lowest point. It shows a degradation in health, mind, and body. At such stage one must make an effort task oneself, "This boredom shows that I have something to learn, some progress to make in myself, some inertia to conquer, some weakness to overcome." 
Why does Laziness Occur?
When one doesn’t practice or try to make oneself better in every aspect of life, it gives rise to laziness. The moment one is satisfied with the results and stops making any changes or progress and starts getting used to the same routine is where the laziness appears. “Oh, it is impossible, I can’t do it, I don’t have the strength, I am not made of that stuff, I don’t have the necessary qualities, I could never do it.” It is absolute laziness… One says, “I am like that, I can’t be otherwise!” It is a refusal to let the divine Grace work in you. It is a justification of your own ill-will. 
Sometimes when there is weakness in the body, it could also result in creating tamas if the weakness is not thrown off by being strong enough to combat the illness. To avoid the physical to going back to the state of tamas it is only by becoming conscious and taking action against the force. 
Laziness is also seen emerging from the lower vital being when it gives way to doubt, dullness, tamas, stupidity, forgetfulness, narrowness, etc. when it is not supported by the higher will and intelligence, it is important to open the physical nature. It can only be done by bringing the spiritual consciousness into all parts of being.
How to Cure Laziness?
The minute one stops going forward, one falls back. It is important to make effort and march forward towards new revelations and realisations. “Become as vast as the world and you will always be at rest. In the thick of action, in the very midst of the battle, the effort, you will know the repose of infinity and eternity.” 
One must always refrain from clinging to old habits and old movements and to always put a will into one’s action. “Become more and more conscious. Certainly tamas is not good, but it is only through surrender to the Divine Consciousness that tamas can be changed.” 
It is by putting hours and days into power to change oneself consciously and making it a habit of discipline, one is sure to accomplish to take the tamas off oneself. …”you become so irrevocably conscious that everything depends on the individual perception, entirely; and naturally, that individual perception [of divine Love] depends on the inadequacy, the inertia, the incomprehension, the incapacity, the cells' inability to hold and keep the Vibration, anyway all that man calls his "character" and which comes from his animal evolution.” 
Transformation of Physical: Why is it the Need of the Hour?
The unwillingness to change has always stayed for a longer period of time for a lazy person. It becomes very difficult for even the strongest mental or vital or even psychic will to overcome this inertia. It was this which had been preventing the elimination of the old movements all along and enabled them to return when they had been pushed out—for it is in the material half-conscious or subconscient that there is the bedrock of the resistance… 
In order to set it right,and progress towards the right direction. It needs to improve in multiple areas which have come up for a first or preliminary transformation. To keep the idea of what is necessary—(1) that the silence and peace shall become a wideness which you can realise as the Self, (2) the extension of the silent consciousness upwards as well so that you may feel its source above you, (3) the presence of peace etc. all the time. 
The best thing to do is to distinguish in oneself the origin of all one's movements—those that come from the light of truth and those that come from the old inertia and falsehood—in order to accept the first and to refuse or reject the others. 
It is to keep trying every second, in each movement to express the highest truth one can perceive, and to be progressive to what seems to you the most true now will no longer be so tomorrow, and that a higher truth will have to be expressed more and more through you. To always remember that whatever path we follow, or the subject we may study, we always reach the same result. The most important thing for an individual is to unify himself around his divine center; that way he becomes a real individual, master of himself and of his destiny.
Content curated by Suchismitha
Read more about Laziness from the works of the Mother and Sri Aurobindo.