The special feature of Ekadasi, as most people know it, is a fast, abstinence from diet. This is how it is usually understood. 'We do not eat on Ekadasi', is what people understand. In this country (India) it has become a routine to be abstemious, if not observe a complete fast on this day. The significance of this particular observance is not merely constituted of a fast, physically, though it is also an essential element; it has other deeper aspects. In fact, the fast is only a practical expression and a symbol of something else that we are expected to do, which is of special significance to our personality. Those who know astronomy as something which tells about the inter-relation of the planetary system, the stellar world, would be aware that we form a part of this planetary or solar system.Astronomy studies the movements of planets and stars, and astrology the effects they produce on the contents of the system. The Ekadasi observance is an astrological phenomenon and it is observed due to this relation we have with some of the planets in the system. The entire personality of ours is tremendously influenced by the movement of planets. There is no use imagining that the planets are above our heads. They are everywhere. There is a relative movement of planets among which the earth is one. The movement of one thing in relation to another is a relative movement. There is no planet which is static. Even the sun is not ultimately static.The whole solar system is moving and rushing towards some huge star, which is eighty million times larger and brighter than the sun, whose light has not yet reached us, as astronomers tell us. We have to understand that there is relative motion amongst planets and we are relatively influenced by the planets., Each planet tells upon our system and we cannot get rid of the influence of theirs as long as we are in this planet, of which we are a part. The gravitational pull of planets has an influence on us.
The sun is said to influence the centre of our personality; hence the sun is called Atmakaraka. He is the soul-influencer of the human body. In the Rig-veda, the sun is identified with the soul of the universe as well as the soul of the individual. The different limbs of our body and different parts of our system are supposed to be influenced by different planets. The sun is capable of influencing the entire being. He is, thus, the Atmakaraka. Karaka is doer, manipulator, director. If there is no sun, we know what difference it makes for us; our digestion becomes sluggish on days when there is no sun. So important is the sun.
The moon is supposed to influence the mind. The mind is also made up of material substance. The mind is not spiritual but material.It is the subtle portion of the material substance of our food. The subtle essence of the food, not only directly taken through the mouth but through all senses, contribute to the make up of the mind or the mind-stuff. Mind is material in a subtle sense, like a mirror which is made of earth-material only, though it shines. Only the mirror is able to reflect light, and not the brick, though it is also made of the earth material. Planets are not spiritual bodies, and yet they influence the mind. The mind's presiding deity is moon. Ekadasi is particularly relevant to this relation of moon and mind. You will find that, when you go deep into the study of astronomy, you have nothing in your body except some planetary influences.
We have certain centres called Chakras in the body. The Chakras are nothing but energy-centres which whirl in some direction as water whirls in a river. These Chakras are neither in the mind nor in the body; they are in the astral body. The moon's influence physically on the body has an influence on the Chakras, which tells upon the mind ultimately. The mind moves through these Chakras. The passage of the mind is through these Chakras, up and down. When this operation takes place consciously, it is called Yoga; When done unconsciously by the mind, it is just influence. When the moon waxes or wanes, the mind is vehemently influenced. So people who are not normal in their minds become very bad on the full-moon and new-moon days.The sun influences the moon and the moon influences the earth. When the influence occurs automatically, we are instruments in the hands of Nature. When it is done consciously, we are said to practise Yoga. Another important aspect is the seat of the mind which is also twofold. You may be living in many houses, of which one or two are your own. Svasthana means 'One's own place.' The mind has several abodes or centres of energy called Chakras, of which two are its own. The seats of the mind in this personality of ours are: 1. the subtle spot in the astral body corresponding to the centre of the two eye-brows, in waking, and 2. the heart, in the state of deep sleep. If it is in the brain, it is active and you, then, do not get sleep, because it refuses to go down. If the mind is midway between the centre of the eye-brows and the heart, it is dream state.So, there is a twofold centre of the mind,—the Ajna-Chakra, or the centre between the eye-brows, and the Anahata Chakra, or the heart. In both these centres, the mind feels at home and is at ease, because it is nearer to itself.
In the two fortnights ekadasis, in its movement, it finds itself at the Ajna Chakra and the Anahata Chakra on the eleventh day. Since these two Chakras are its own abode, the mind is at home here, i.e., it gets concentrated and collected easily. You are capable of concentration when the mind is naturally in its home.So, the Ekadasi day in both fortnights is the occasion when the mind finds itself in its place—in the bright fortnight in the Ajna Chakra, and in dark fortnight in the Anahata Chakra. Seekers and Yogis take advantage of these two days and try to practise deep meditation. Vaishnavas treat Ekadasi as a very holy day and also observe a fast on that day.