Thank you for Huxley's article. Generally speaking, a concept, an idea, and a thought, are much the same thing, and can be described as an imaginary picture representing some real state of affairs. But this 'representation' is not simply a photographic reproduction (in the mind) of the real state of affairs in question. In a very simple case, if I now imagine or think of some absent object, the image that I have bears some sort of resemblance to the absent object.
But suppose I want to think about something like 'the British Constitution'. I cannot simply produce an imaginary picture 'looking like' the British Constitution, because the B.C. does not 'look like' anything. What happens is that, over the years, I have built up a complex image, partly visual, partly verbal, and perhaps also with elements from other senses; and this complex image has an internal structure that corresponds to that of the B.C., at least in so far as I have correctly understood it. If, in my studies of the British Constitution I have consulted faulty authorities, or omitted part of it, these faults or omissions will be represented in this complex image. Whenever I wish to think about the B.C. (or even whenever anybody mentions it) this complex image comes to my mind, and it is with reference to it that I (for example) answer questions about the B.C. This complex image is a concept—it is my concept of the B.C. With luck, it may correspond fairly closely with the original thing, but most probably it is a very misleading representation. (Note that, since the essence of the concept is in the structure of the complex image, and not in the individual images that make up the complex image, it is quite possible to have a number of different complex images, but all with the same structure, to represent the real state of affairs in question. Here, the concept remains the same, though the image is different. Thus, in the world of art, it is possible to express the same idea either in music or in painting.)
Now all conceptual thinking is abstract; that is to say, the thought or concept is entirely divorced from reality, it is removed from existence and is (in Kierkegaard's phrase) sub specie aeterni. Concrete thinking, on the other hand, thinks the object while the object is present, and this, in the strict sense of the words, is reflexion or mindfulness. One is mindful of what one is doing, of what one is seeing, while one is actually doing (or seeing) it. This, naturally, is very much more difficult than abstract thinking; but it has a very obvious advantage: if one is thinking (or being mindful) of something while it is actually present, no mistake is possible, and one is directly in touch with reality; but in abstract thinking there is every chance of a mistake, since, as I pointed out above, the concepts with which we think are composite affairs, built up of an arbitrary lot of individual experiences (books, conversations, past observations, and so on).
What Huxley is getting at, then, is simply this. As a result of our education, our books, radios, cinemas, televisions, and so on, we tend to build up artificial concepts of what life is, and these concepts are grossly misleading and are no satisfactory guide at all to real life. (How many people, especially in the West, derive all their ideas about love from the cinema or T.V.—no wonder they run into difficulties when they begin to meet it as it is in reality!) Huxley is advocating a training in mindfulness (or awareness), satisampajañña—in thinking about life as it is actually taking place—instead of (or, at least, as well as) the present training in purely abstract thinking. In this way, so he maintains—and of course he is quite right—, people will be better fitted for dealing with life as it really is. Does this answer your question?