The Taoist Farmer 道人

近塞上之人有善術者，馬無故亡而入胡，人皆弔之 。其父曰：「此何遽不為福乎！」
Among the people who lived close to the border, there was a man who led a righteous life. Without reason, his horse escaped, and fled into barbarian territory. Everyone pitied him, but the old man said : "what makes you think this is not a good thing?"

居數月，其馬將胡駿馬而歸，人皆賀之。其父曰：「此何遽不能為禍乎！」
Several months later, his horse returned, accompanied by a superb barbarian stallion. Everyone congratulated him. But the old man said: "what makes you think this is cannot be a bad thing?"

家富良馬，其子好騎，墮而折其髀，人皆弔之。其父曰：「此何遽不為福乎！」
The family was richer from a good horse, his son enjoyed riding it. He fell and broke his hip. Everyone pitied him, but the old man said: "what makes you think this is not a good thing!"

居一年，胡人大入塞，丁壯者引弦而戰，近塞之人，死者十九，此獨以跛之故，父子相保
One year later, a large party of barbarians entered the border. All the valid men drew their bows and went to battle. From the people living around the border, nine out of ten died. But just because he was lame, the old man and his son were both spared.

故福之為禍，禍之為福，化不可極，深不可測也。
Thence, good fortune turns into bad fortune, and bad fortune turns into good fortune. These changes never reach an end, their complexity can never be fathomed.

From Huainanzi via The China History Forum

"A Chinese story, kind of a Taoistic story about a farmer. One day, his horse ran away, and all the neighbors gathered in the evening and said 'that's too bad.' He said 'maybe.' Next day, the horse came back and brought with it seven wild horses. 'Wow!' they said, 'Aren't you lucky!' He said 'maybe.' The next day, his son grappled with one of these wild horses and tried to break it in, and he got thrown and broke his leg. And all the neighbors said 'oh, that's too bad that your son broke his leg.' He said, 'maybe.' The next day, the conscription officers came around, gathering young men for the army, and they rejected his son because he had a broken leg. And the visitors all came around and said 'Isn't that great! Your son got out.' He said, 'maybe.'"

From Psychedelics and Religious Experience, by Alan Watts

Some Taoist texts