任何事物都有现象与本质两个方面。所谓本质,就是事物的相对稳定的内部联系,而现象则是为人们的感官可以感知的事物的表面特征和外部联系,是事物本质的反映。现象比本质丰富生动,又易于被人感知,因此它是认识本质的向导,认识本质必须从现象入手。例如,要了解黄河凌汛的成因,首先要掌握有关凌汛的各种现象。凌汛是冰坝阻塞水流、抬高水位的现象。黄河凌汛发生的时间是初冬河水开始封冻和春季河水开始解冻的两个时期,发生的地点限于上游河套一段和下游山东境内,其共同点是河流由低纬度向高纬度流的河段。综合上述各种现象,我们就能找到凌汛的成因这个“本质”:上段(低纬度)河水没结冰,流速快;下段(高纬度)由于气温低,河水已结冰,形成冰坝,阻塞水流,因而抬高了水位,形成凌汛。 Everything has both phenomena and essence. The so-called essence is the relatively stable internal relations of things, and the phenomena are the surface features and external relations of the things that people’s senses can perceive, and they are the reflection of the nature of things. Phenomenon is richer and more vivid than nature, and it is easy to be perceived by people. Therefore, it is a guide for understanding nature, and the nature of understanding must start from the phenomenon. For example, to understand the causes of the Yellow River eel, we must first master the various phenomena related to eel eel. Ling Xiao is the phenomenon that the ice dam blocks water flow and raises the water level. The occurrence time of the Yellow River Camphor was two periods when the water in the early winter began to freeze and the spring began to thaw in the spring. The site of the occurrence was limited to the upper reaches of the Hetao section and the lower reaches of Shandong, and the common point was the river section from the low latitude to the high latitude. By combining the above-mentioned phenomena, we can find the essence of Ling Xiao’s “essence”: in the upper segment (low latitudes), the river does not freeze, and the flow velocity is fast; in the lower segment (high latitude), the ice has formed due to the low temperature, and the ice dam has formed. , Blocking the flow of water, thus raising the water level, the formation of Ling Xiao.