Santayana would reject the 'bundle of perceptions' theory of the self as espoused by David Hume. He says in his chapter on Objections to Belief in Substance (Scepticism and Animal Faith): “But it is utterly impossible that one perception should perceive another, and it is improper to call an intuition a perception when it has no existing object.”
There appears to be implicit in the Humean analysis an inner mental subject surveying an inner mental object. That internal division is assumed by classic meditation techniques which involve control of the mind, watching the thoughts arising and so forth. Why is a mistaken doctrine being accepted as a basis for practice? I think the answer lies in ripeness. While you are still green it is useless to mouth the slogans of advaita on the basis of an intellectual understanding of its philosophy. You have to ripen before you naturally fall. Ramakrishna said as much to Vivekananda when they first met. You live where you are until you realise a different level.
By observing the stream of consciousness one is accepting the dualistic stance that is normal alienation. However by continuous attention to it and analysis of its specious reality its grip is progressively weakened. One then may experience an unbroken stream of consciousness from time to time which is naturally blissful. Eckhart Tolle reports that his bliss came from the sudden breaking of the negative commentary of the divided self which was causing him to sink into despair. That absorption in the unbroken flow of consciousness is the report of mystics from all the great traditions.
When Blake writes:
“To cast off Bacon, Locke & Newton from Albions covering”
“To take off his filthy garments, & clothe him with Imagination”
“To cast aside from Poetry, all that is not Inspiration”
LOCKE sank into a swoon;
The Garden died;
God took the spinning-jenny
Out of his side.
they are not indulging in overblown rhetoric. They are pointing to the consolidation of alienation by philosophy and scientism. Certainly internal division has always been an element of human psychology but the intensity and virtual ratification of it as an element of human nature has increased in the modern age.
In a book written by Maurice Nicoll Psychological Commentaries II based on the teachings of Gurdjieff and Ouspensky that I came across recently he has a note on self-observation. (Great Amwell House, September 20, 1947)
Now the Work says, for instance, that self-observation is a method of self-change. It says this quite early........Now a man should observe what he observes. To observe is difficult. It needs a conscious effort. You cannot observe yourself mechanically. That certainly will change nothing. But in such a case, if you become cleverer, you will begin to observe that you always observe only two or three things over and over again. This will not separate you from your mechanical self. For has not observation now become a very part of your mechanical self? The function of Observing 'I' is to move inwards, more and more deeply, so that more and more of yourself can be seen by it. If Observing 'I' remains on the surface of yourself it cannot perform its real task, which is to make a man more and more objective to himself, more and more aware of what he has hitherto calmly taken as himself. If self-observation is truly carried out and not blocked by some strong attitude or picture that the man or woman cannot observe, then it leads to seeing bits of one's life and behaviour all together.