“I expect nothing of man, and disown the race. The only folly is expecting what is never attained; man is most contemptible when compared with his own pretensions. It is better to laugh at man from outside the universe, than to weep for him within.”

According to The quote verifier: who said what, where, and when (2006), Keyes, Macmillan, p. 91 ISBN 0312340044 , the cover of a trade magazine once credited this observation to Churchill, but it dates back well into the nineteenth century, and has been variously attributed to Henry Ward Beecher, Oliver Wendell Holmes, w:Theodore Roosevelt, w:Thomas Jefferson, w:Will Rogers and Lord Palmerston, among others. One documented use in Social Silhouettes (1906) by George William Erskine Russell, p. 218 wherein a character attributes the saying to Lord Palmerston.
Misattributed

Letter, written in collaboration with John Gay, to William Fortescue (23 September 1725).
A similar remark was made in a letter to John Gay (16 October 1727): "I have many years magnify'd in my own mind, and repeated to you a ninth Beatitude, added to the eight in the Scripture: Blessed is he who expects nothing, for he shall never be disappointed."
Variant: Blessed is he who expects nothing, for he shall never be disappointed.
Context: "Blessed is the man who expects nothing, for he shall never be disappointed" was the ninth Beatitude which a man of wit (who, like a man of wit, was a long time in gaol) added to the eighth.

Source: Assassin's Apprentice

Variant translation:
It is very important to give advice to a man to help him mend his ways. It is a compassionate and important duty. However, it is extremely difficult to comprehend how this advice should be given. It is easy to recognise the good and bad points in others. Generally it is considered a kindness in helping people with things they hate or find difficult to say. However, one impracticality is that if people do not take in this advice they will think that there is nothing they should change. The same applies when we try to create shame in others by speaking badly of them. It seems outwardly that we are just complaining about them. One must get to know the person in question. Keep after him and get him to put his trust in you. Find out what interests he has. When you write to him or before you part company, you should express concrete examples of your own faults and get him to recall to mind whether or not he has the same problems. Also positively praise his qualities. It is important that he takes in your comments like a man thirsting for water. It is difficult to give such advice. We cannot easily correct our defects and weak points as they are dyed deeply within us. I have had bitter experience of this.
Hagakure (c. 1716)
Context: To give a person one's opinion and correct his faults is an important thing. It is compassionate and comes first in matters of service. But the way of doing this is extremely difficult. To discover the good and bad points of a person is an easy thing, and to give an opinion concerning them is easy, too. For the most part, people think that they are being kind by saying the things that others find distasteful or difficult to say. But if it is not received well, they think that there is nothing more to be done. This is completely worthless. It is the same as bringing shame to a person by slandering him. It is nothing more than getting it off one's chest.
To give a person an opinion one must first judge well whether that person is of the disposition to receive it or not. One must become close with him and make sure that he continually trusts one's word. Approaching subjects that are dear to him, seek the best way to speak and to be well understood. Judge the occasion, and determine whether it is better by letter or at the time of leave-taking. Praise his good points and use every device to encourage him, perhaps by talking about one's own faults without touching on his, but so that they will occur to him. Have him receive this in the way that a man would drink water when his throat is dry, and it will be an opinion that will correct faults.
This is extremely difficult. If a person's fault is a habit of some years prior, by and large it won't be remedied. I have had this experience myself. To be intimate with all one's comrades, correcting each other's faults, and being of one mind to be of use to the master is the great compassion of a retainer. By bringing shame to a person, how could one expect to make him a better man?

Essays, The Other Six Deadly Sins (1941)

A New Kind of Man
Song lyrics, A Sense of Wonder (1985)

"On Wit and Humour"
Lectures on the English Comic Writers (1819)

Lecture XXX, Atheism alone a Positive View
Lectures on the Essence of Religion http://www.marxists.org/reference/archive/feuerbach/works/lectures/index.htm (1851)