历史上的三次数学危机,分别发生在公元前5世纪、公元17世纪和19世纪.第一次是由于无理数的出现;第二次是由于微积分理论的不严密;第三次是由于集合中悖论的出现.现在我们把这三次数学危机做一个简单介绍. The three mathematical crises in history occurred in the 5th century BC, the 17th century and the 19th century respectively. The first was due to the appearance of irrational numbers; the second was due to the imprecise theory of calculus; and the third was due to the collection The emergence of the paradox Now we make a brief introduction to these three mathematical crises.