“For a true artist, difficulties become opportunities and clouds become solid present.”

Changing My Mind, Among Others : Lifetime Writings (1982), p. 76; also in Change Your Brain (2000), p. 72
Context: To describe externals, you become a scientist. To describe experience, you become an artist. The old distinction between artists and scientists must vanish. Every time we teach a child correct usage of an external symbol, we must spend as much time teaching him how to fission and reassemble external grammar to communicate the internal. The training of artists and creative performers can be a straightforward, almost mechanical process. When you teach someone how to perform creatively (ie, associate dead symbols in new combinations), you expand his potential for experiencing more widely and richly.

This quote is commonly attributed to Churchill, but appears in the "Red Herrings: False Attributions" appendix of Churchill by Himself : The Definitive Collection of Quotations (2008) by Richard Langworth, without citation as to where it originates.
In American Character, a 1905 address by Brander Matthews, a similar quotation is attributed to L. P. Jacks ( link http://hdl.handle.net/2027/mdp.39015059451156?urlappend=%3Bseq=238).
""Our civilization is a perilous adventure for an uncertain prize... Human society is not a constructed thing but a human organization... We are adopting a false method of reform when we begin by operations that weaken society, either morally or materially, by lower its vitality, by plunging it into gloom and despair about itself, by inducing the atmosphere of the sick-room, and then when its courage and resources are at a low ebb, expecting it to perform some mighty feat of self-reformation... Social despair or bitterness does not get us anywhere... Low spirits are an intellectual luxury. An optimist is one who sees an opportunity in every difficulty. A pessimist is one who sees a difficulty in every opportunity... The conquest of great difficulties is the glory of human nature." L. P. Jacks, quoted in American character, by Brander Matthews, 1906
Misattributed
Variant: A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty.

Source: Growing Up Absurd (1956), p. 176.

Given (2005), Sabbaths 2001

Source: Nervous Stillness on the Horizon (2006), P. 51 (Gunter Brus.Nach uns die Malflut!Pheoretische Poesien.Klagenfurt:Ritter Verlag,2003, p. 135)

1960's, Conversations with Samuel Beckett and Bram van Velde' (1965 - 1969)

"Anton Ego" in Ratatouille (2007)
Context: In many ways, the work of a critic is easy. We risk very little, yet enjoy a position over those who offer up their work and their selves to our judgment. We thrive on negative criticism, which is fun to write and to read. But the bitter truth we critics must face, is that in the grand scheme of things, the average piece of junk is probably more meaningful than our criticism designating it so. But there are times when a critic truly risks something, and that is in the discovery and defense of the new. The world is often unkind to new talents, new creations. The new needs friends. Last night, I experienced something new; an extraordinary meal from a singularly unexpected source. To say that both the meal and its maker have challenged my preconceptions about fine cooking, is a gross understatement. They have rocked me to my core. In the past, I have made no secret of my disdain for Chef Gusteau's famous motto, "Anyone can cook". But I realize — only now do I truly understand what he meant. Not everyone can become a great artist, but a great artist can come from anywhere. It is difficult to imagine more humble origins than those of the genius now cooking at Gusteau's, who is, in this critic's opinion, nothing less than the finest chef in France. I will be returning to Gusteau's soon, hungry for more.