Our end is to follow the gods. And the essence of good consists in the proper use of impressions. So, make a practice at once of saying to every strong impression: ‘An impression is all you are, not the source of the impression.’ Then test and assess it with your criteria, but particularly one. Ask, ‘Is this something that is, or is not, in my control?’ – Epictetus, Enchiridion 1.5
Higher impressions produce a liberating effect. – P.D. Ouspensky
Things that make you angry, make you hate people or give you a taste of coarseness or violence, all these impressions come from low worlds. But we can improve impressions, this is our only chance. – P.D. Ouspensky
If you remember yourself sufficiently, you can stop certain impressions, you can isolate yourself- they will come but they will not penetrate. – P.D. Ouspensky
Of the three kinds of food, the most important for us is impressions. – P.D. Ouspensky
In the ordinary state man makes very little use of impressions. – P.D. Ouspensky

Beautiful Impressions, whether natural or man-made, function as a catalyst for higher centers. – Robert Burton
From P.D. Ouspensky, In Search of the Miraculous
In ordinary conditions of life, we do not remember ourselves; we do not remember, that is, we do not feel ourselves, are not aware of ourselves at the moment of a perception, of an emotion, of a thought or of an action. If a man understands this and tries to remember himself, every impression he receives while remembering himself will, so to speak, be doubled. In an ordinary psychic state, I simply look at a street.
But if I remember myself, I do not simply look at the street; I feel that I am looking, as though saying to myself: ‘I am looking.’ Instead of one impression of the street there are two impressions, one of the street and another of myself looking at it. This second impression, produced by the fact of my remembering myself, is the ‘additional shock.’ Moreover, it very often happens that the additional sensation connected with self-remembering brings with it an element of emotion, that is, the work of the machine attracts a certain amount of ‘carbon’ 12 to the place in question.
Efforts to remember oneself, observation of oneself at the moment of receiving an impression, observation of one’s impressions at the moment of receiving them, registering, so to speak, the reception of impressions and the simultaneous defining of the impressions received, all this taken together doubles the intensity of the impressions and carries do 48 to re 24.
…The effort which creates this ‘shock’ must consist in work on the emotions, in the transformation and transmutation of the emotions. This transmutation of the emotions will then help the transmutation of si 12 in the human organism. No serious growth, that is, no growth of higher bodies within the organism, is possible without this transmutation. The idea of this transmutation was known to many ancient teachings as well as to some comparatively recent ones, such as the alchemy of the Middle Ages. But the alchemists spoke of this transmutation in the allegorical forms of the transformation of base metals into precious ones. In reality, however, they meant the transformation of coarse ‘hydrogens’ into finer ones in the human organism, chiefly of the transformation of mi 12.
If this transformation is attained, a man can be said to have ‘achieved what he was striving for, and it can also be said that, until this transformation is attained, all results attained by a man can be lost because they are not fixed in him in any way; moreover, they are attained only in the spheres of thought and emotion. Real, objective results can be obtained only after the transmutation of mi 12 has begun. Alchemists who spoke of this transmutation began directly with it. They knew nothing, or at least they said nothing, about the nature of the first volitional ‘shock.’ It is upon this, however, that the whole thing depends. The second volitional ‘shock’ and transmutation become physically possible only after long practice on the first volitional ‘shock,’ which consists in self-remembering, and in observing the impressions received.
From G. I. Gurdjieff, Views from the Real World
The full realization and precise determination in man of that totality of functioning whose factors are constituted from impressions coming from outside is called the “outer world” of man. And the full realization of the other totality, whose factors have arisen from automatically flowing “experiences” and from reflexes of the organism—notably of those organs whose specific character is transmitted by heredity—is called the “inner world” of man.
In relation to these two worlds, man appears in reality to be merely a slave, because his various perceptions and manifestations cannot be other than conformable to the quality and nature of the factors making up these totalities. He is obliged, in relation to his outer world as well as his inner world, to manifest himself in accordance with the orders received from any given factor of one or the other totality.
He cannot have his own initiative; he is not free to want or not to want, but is obliged to carry out passively this or that “result” proceeding from other outer or inner results. Such a man, that is to say, a man who is related to only two worlds, can never do anything; on the contrary, everything is done through him. In everything, he is but the blind instrument of the caprices of his outer and inner worlds.
The highest esoteric science calls such a man “a man in quotation marks.” In other words he is named a man and at the same time he is not a man. He is not a man such as he should be, because his perceptions and his manifestations do not flow according to his own initiative but take place either under the influence of accidental causes or in accordance with functioning that conforms to the laws of the two worlds.
In the case of “a man in quotation marks,” the “I” is missing and what takes its place and “fills its role” is the factor of initiative proceeding from that one of the two above-mentioned totalities in which the center of gravity of his general state is located.
The “I” in a real man represents that totality of the functioning of his general psyche whose factors have their origin in the results of contemplation, or simply in the contact between the first two totalities, that is, between the factors of his inner world and of his outer world.
The totality of the manifestations of this third function of the general psyche of man also represents a world in itself, but in this case it is the third world of man. And thus, this third world of man is, strictly speaking, as the ancient sciences understood, the real “inner world of man” as opposed to the real “outer world.”
To read more from these authors, see: https://www.amazon.com/Ouspensky or https://www.amazon.com/Search-Miraculous and https://www.amazon.com/gurdjieff.
Related articles in the FourthWayToday.org magazine include: https://fourthwaytoday.org/reality-2/ and https://fourthwaytoday.org/awakening-as-the-third-state-of-consciousness/, among many others.