火,指“可燃物质的快速燃烧,产生热量,通常还有火焰”,本身是一种自然现象。当火在自然界中自行燃烧时,它尚不具有工具的性质,就象石头的自然存在不是工具一样。正因为如此,恩格斯把火称为“一种自然力”。然而,作为一种化学反应现象,火在燃烧中会释放出热能。当人用火去从事活动,火便成为一种工具。与一般工具所不同的特点是,它不是以固体材料的形式出现,不需要人体供给能量,而是以燃烧的能量释放过程出现,因而火是一种能量性工具,并具有极强的文化创造功能。恩格斯指出:“就世界性的解放作用而言,摩擦生火还是超过了蒸汽机,因为摩擦生火第一次使人支配了一种自然力,从而最终把人同动物界分开。”“甚至把这种发现看作人类历史的开端。”一旦为人类所利用,火便成为人类社会不可或缺之物,创造出不尽其数的物质财富,使人类走上了文明之路。 Fire, referring to the “rapid burning of combustible material, heat, usually there is a flame,” is a natural phenomenon in itself. When fire burns itself in nature, it does not yet have the nature of a tool, just as the natural existence of stone is not a tool. Because of this, Engels called the fire “a natural force.” However, as a chemical reaction, fire releases heat during combustion. When people use fire to engage in activities, fire becomes a tool. What distinguishes it from other general tools is that it does not appear as a solid material, it does not need the body to supply energy, but rather emerges as a burning energy release, so that fire is an energetic tool with a strong cultural creation Features. Engels pointed out: “As far as the worldwide liberation is concerned, friction or fire exceeds steam engines, for the first time frictional fires dominate a natural force that eventually separates humans from the animal kingdom.” “Even putting such a discovery As the beginning of human history. ”Once used by mankind, fire has become an indispensable part of human society and has created an endless amount of material wealth, enabling mankind to embark on the path of civilization.