Chapter 46 <One cannot step into the same river even once>

The ancient Greek philosopher Heraclitus believed that things in the world are constantly moving and changing like the water in a river.He said a famous saying: You can't walk into the same river twice, because when you walk into the river for the second time, the water has already changed. Heraclitus had a student named Cratylus.He thought his teacher was not thorough enough, and believed that one cannot step into the same river even once, because when you are about to enter, the river has undergone countless changes.He doesn't even think that something can even have a name, because when you say the name, it has become something else.

Materialist dialectics believes that objective things are constantly moving and changing due to internal contradictions, but things have their relative stability and qualitative stipulations during their movement and change. For example, if we plant a tree, it grows and changes all the time, but within a certain period of time, no matter how fast it grows, it is still a tree.If it is a willow tree, then before it is sawn down to make something else, it is a willow tree, and it cannot be another tree at the same time, that is to say, it has its own qualitative determination. The mistake of Cratylus lies in exaggerating the movement and change of things one-sidedly, denying the relative stillness of things, and believing that things are fleeting and ever-changing without the slightest certainty, thus falling into the sophistry of relativism.On this view, our knowledge of anything is impossible.

In fact, denying the relative certainty and qualitative regulation of things means denying the change of things.Because the so-called change means that one thing evolves into another thing, or things change from one state to another.How can it be said what change is, if there is no certainty about the thing itself or the state of the thing? So Lenin pointed out sharply: This Cratylus turned Heraclitus' dialectics into sophistry. ("Lenin's Philosophical Notes", 1956 edition, p. 320) From the point of view of the basic laws of formal logic, Cratylus' sophistry is due to the denial of the objective basis of the law of identity, that is, the denial of the relative stability of things Sexual and qualitative prescriptiveness.