WE have studied the first process of thought — the way in which every idea opens out in many directions. We have now to consider the second process — the way in which our attention passes on from one idea to another and forms a flow of thought. It is a matter almost of common knowledge that our attention travels among thoughts very much in the same way as our body moves about among things. So close is the similarity that we may say that the attention seems actually to walk on two-feet from one mental image or idea to another.

Suppose, for example, I start to think about a cow and a few moments later I find myself thinking about a curio shop. There is a reason for this, which I can discover by tracing back in memory the series of preceding thoughts. Before “curio shop” there was a picture of some old artistic glassware; before that was “glass”, before that “bottle”, before that “milk-bottle” — and so back to “milk” and “cow”.

What is to be noticed now is not so much the procession of memories as the series of forgettings. Every operation of memory includes an act of forgetting many other things; what remains after the forgetting is in the focus of consciousness and is called a memory. Thus, “cow” and “milk” stand together in one compound natural picture. My attention contains both “cow” and “milk” at one moment. They are part of a unit idea. Next, “cow” is set aside or forgotten and “milk” connects with “bottle”, and produces one unit composed of “milk” and “bottle”, that is, milk in a bottle. There is not a unit “cow and bottle”; such a unit would be a less familiar and more unstable compound idea. It will not arise in the flow of ideas thrown up by subconscious association, but would require an act of will (such as we are using now) to produce and hold it, and the least slackening of that will would result in the breaking up of that compound picture, it being deficient in unity.

Here let me refer to modern art. If in a picture various things presented together are not in the familiar groupings of nature, the whole is unpleasing though the parts taken separately may be very pleasing. We all feel there is no beauty in such a combination, though we may not all understand the reason for it, which is that beauty is the mind’s delight in unity. We shall probably call it a restless picture. But we must remember that in the coterie of artists who enjoy those pictures, and can enjoy them for a long time, there is a background of mental habits which have lingered upon an obscure relationship between those odd parts and have made them familiar associates in such special workings of the mind, outside the experience of ordinary men.

We see now that the flow of thoughts, or rather ideas, in the course of ordinary mental drift or day-dreaming is due to subconscious associations, which in their turn were originally formed by conscious observation and thinking. It is analogous to body processes such as walking. There is, as I have already mentioned, a very close resemblance to the use of two legs in walking.

There are seven stepping stone between my kitchen entrance and the tool room. Call them A to G. I have my left foot on A and my right foot on B and I am on the move, or, in other words, I have inherent momentum. My left foot lifts off A, swings over to C and plants itself there, and then my right foot lifts from B and moves on to D, and so my body is carried along on what seems a continuous movement, which however consists also of a series of stoppages on resistant stepping-stones. The successive ideas in the mind are like the stepping-stones, among which B is contiguous to A and C, and F is contiguous to E and G, but A is not contiguous to C, nor E to G.

Now another point. I could if I wished stop and stand on one stepping-stone. Or poise my attention on one of the ideas — say milk. If I concentrate on milk and do not go on to bottle nor back to cow, milk will begin to give up its secrets — or, it will sprout all its adjacent associations in accordance with the explanation I have already given in connection with the Four Roads of Thought. Perhaps there will be a hundred of those arrows. The more there are the better, for they bring me nearer to knowing what milk really is, that is, to understanding it. The quick and ready associations will be such as baby, calf, cat, cream, butter, cheese, water, liquidity, white color, goat’s milk, cocoanut milk, etc. More obscure ones will arise according to my special knowledge.

If now I cease my concentration the drift will begin again, beginning with any one of the arrows. Consideration of this will show us how at every moment there is a choice — a fork in the road of thought. The parting of the ways is small, but soon they are far asunder — a fact which shows how much my future depends upon every step in my thought. It is no wonder that the ancient psychologists of India, holding that what a man thinks determines what he will become, developed a system of mental exercises, termed Raja Yoga, calculated to speed men swiftly onwards to the fulfilment of human life in the perfection of mind, and its full opening to those spiritual realities which it only very dimly perceives in the case of the average person at the present time.

A diagram will show us the divergence of the thought-streams :

body moves, common knowledge, consciousness, memory, mental image, one moment, subconscious, unity