He who has nothing external that can divert him must find pleasure in his own thoughts, and must conceive himself what he is not; for who is pleased with what he is? He then expiates in boundless futurity, and culls from all imaginable conditions that which for the present moment he should most desire, amuses his desires with impossible enjoyments, and confers upon his pride unattainable dominion. The mind dances from scene to scene, unites all pleasures in all combination, and riots in delights which nature and fortune, with all their bounty, cannot bestow.

In time some particular train of ideas fixes the attention; all other intellectual gratifications are rejected; the mind, in weariness or leisure, recurs constantly to the favorite conception, and feasts on the luscious falsehood whenever she is offended with the bitterness of truth. By degrees the reign of fancy is confirmed; she grows first imperious, and in time despotic. Then fictions begin to operate as realities, false opinions fasten upon the mind, and life passes in dreams of rapture or of anguish.

There are... otherwise quite decent people who are so dull of nature that they believe that they must attribute the swift flight of fancy to some illness of the psyche, and thus it happens that this or that writer is said to create not other than while imbibing intoxicating drink or that his fantasies are the result of overexcited nerves and resulting fever. But who can fail to know that, while a state of psychical excitement caused by the one or other stimulant may indeed generate some lucky and brilliant ideas, it can never produce a well-founded, substantial work of art that requires the utmost presence of mind.

To muse for long unwearied hours with my attention riveted to some frivolous device upon the margin, or in the typography of a book — to become absorbed for the better part of a summer's day in a quaint shadow falling aslant upon the tapestry, or upon the floor — to lose myself for an entire night in watching the steady flame of a lamp, or the embers of a fire — to dream away whole days over the perfume of a flower — to repeat monotonously some common word, until the sound, by dint of frequent repetition, ceased to convey any idea whatever to the mind — to lose all sense of motion or physical existence in a state of absolute bodily quiescence long and obstinately persevered in — Such were a few of the most common and least pernicious vagaries induced by a condition of the mental faculties, not, indeed, altogether unparalleled, but certainly bidding defiance to any thing like analysis or explanation.

A mind too active is no mind at all. — Infirmity

What is it that is whirling the mind? Imagination, creative activity. Stop creation and you know the truth. All power of creation must stop, and then you know the truth at once.

There are tumults of the mind, when, like the great convulsions of Nature, all seems anarchy and returning chaos; yet often, in those moments of vast disturbance, as in the strife of Nature itself, some new principle of order, or some new impulse of conduct, develops itself, and controls, and regulates, and brings to an harmonious consequence, passions and elements which seem only to threaten despair and subversion.

Hard to restrain, unstable is this mind; it flits wherever it lists. Good it is to control the mind. A controlled mind brings happiness.

The senses, feelings, and thoughts must be allowed to be spontaneous in the faith that they will then order themselves harmoniously. To try to control the mind forcefully is like trying to flatten out waves with a board, and can only result in more and more disturbance.

We are disturbed not by what happens to us, but by our thoughts about what happens.

Freedom from Uncontrolled Thinking A big habit I’m working on is trying to turn off my “monkey mind.” When we’re children, we’re pretty blank slates. We live very much in the moment. We essentially just react to our environment through our instincts. We live in what I would call the “real world.” Puberty is the onset of desire — the first time you really, really want something and you start long-range planning. You start thinking a lot, building an identity and an ego to get what you want. If you walk down the street and there are a thousand people in the street, all thousand are talking to themselves in their head at any given point. They’re constantly judging everything they see. They’re playing back movies of things that happened to them yesterday. They’re living in fantasy worlds of what’s going to happen tomorrow. They’re just pulled out of base reality. That can be good when you do long-range planning. It can be good when you solve problems. It’s good for us as survival-and-replication machines. I think it’s actually very bad for your happiness. To me, the mind should be a servant and a tool, not a master. My monkey mind should not control and drive me 24/7. I want to break the habit of uncontrolled thinking, which is hard. [4] A busy mind accelerates the passage of subjective time. There is no endpoint to self-awareness and self-discovery. It’s a lifelong process you hopefully keep getting better and better at. There is no one meaningful answer, and no one is going to fully solve it unless you’re one of these enlightened characters. Maybe some of us will get there, but I’m not likely to, given how involved I am in the rat race. The best case is I’m a rat who might be able to look up at the clouds once in a while. I think just being aware you’re a rat in a race is about as far as most of us are going to get. [8] The modern struggle: Lone individuals summoning inhuman willpower, fasting, meditating, and exercising… Up against armies of scientists and statistici

a human mind is a wandering mind, and a wandering mind is an unhappy mind.

We must not think too much: people go mad if they think too much.

"The most practical of all methods for controlling the mind is the habit of keeping it busy with a definite purpose, backed by a definite plan."
And
"A man whose mind is filled with fear not only destroys his own chances of intelligent action, but he transmits these destructive vibrations to the minds of all who come in contact with him, and destroys, also, their chances."

An untamed mind is a minefield.