自然具有三种基本的含义：一个事物的基本性质或本质、物质世界的整体和初始状态。马克思的唯物主义自然观与黑格尔、费尔巴哈相区分，马克思始终坚持自然界的优先地位，拒斥神创论，而黑格尔和费尔巴哈一个是基督教的代言人，一个是新教的代言人。这在马克思对“自然界是人的无机身体”这一命题中得到集中的体现，马克思认为人作为客观的、有机的生物，也是依赖于无机性质作为自己物种存在的一部分，因此有机体人类像所有物种一样在其自身中包括其无机存在。所以马克思的分析科学、唯物、辩证地运用有机和无机，超越了简单的机械论和工具主义。马克思同时重视劳动改造自然的作用，人虽然不能创造物质但是能够通过劳动改变物质的具体形态，这与黑格尔、费尔巴哈一样都是将对待自然的理论态度和实践态度相结合。劳动是人与自然的物质变换过程，在资本主义下，出现了物质变换紊乱的现象，这启示我们应该合理调节当今社会的生产方式，避免在经济发展过程中出现资源枯竭、环境恶化的问题，合理地协调人与自然物质变换。资本主义物质变换导致了自然环境的破坏和过剩的贫困人口，如何解释贫困人口的产生成为一个重要的问题。马尔萨斯将过剩人口看成自然的、不可改变的，救济他们只能造成更大规模的贫困。资本主义同时也带来了先进的科学技术，李比希的化学理论促进了第三次农业革命，使粮食生产力得到极大的提高，这有力地打击了马尔萨斯的人口论，证明了生产力的发展速度有可能跟上人口增长速度。马克思认为马尔萨斯脱离了现实的历史看待人口规律，为反动的统治辩护，正是资本主义的固有矛盾导致了过剩的人口。当代的一些学者指责马克思对马尔萨斯的批评是政治的，并且有意忽视了自然的极限，这是缺乏证据的，马克思没有否认自然的极限，而是认为工业的进步能够使人具有越来越强的力量控制自然为人类服务。马克思没有为控制自然设置道德或现实的界限，认为应该合理、共同地调节人与自然的物质变换，实现人的自由全面发展。这在某种程度上具有普罗米修斯的精神，与近代启蒙思想相一致，但是这并非不尊重客观规律，人类始终要面对必然王国，尽管这个领域会随着生产力的扩大而缩小，这也不是所谓的“人类中心主义”。在社会主义新中国，深入研究马克思的自然思想对我们认识和解决生态危机、协调人与自然的关系具有重要意义。解决人口与环境问题需要重视生态文明建设，走人与自然和谐共生的发展道路。

Nature has three basic meanings: the basic nature or essence of a thing, the whole and initial state of the material world. Marx's materialistic view of nature is different from that of Hegel and Feuerbach. Marx always insists on the priority of nature and rejects creationism, while Hegel and Feuerbach are the spokespersons of Christianity and the other is Protestantism. spokesperson. This is concentrated in Marx's proposition that “nature is the inorganic body of man”. Marx believed that man, as an objective and organic creature, also depends on the inorganic nature as a part of his own species existence. Therefore, the organic human being is like all species. The same includes within itself its inorganic existence. Therefore, Marx's analytical science, materialism, and dialectical use of organic and inorganic, go beyond simple mechanism and instrumentalism. Marx also attached importance to the role of labor in transforming nature. Although humans cannot create material, they can change the specific form of material through labor. This is the same as Hegel and Feuerbach who combined the theoretical and practical attitudes towards nature. Labor is the process of metabolism between man and nature. Under capitalism, there is a phenomenon of disordered metabolism. This enlightens us to rationally adjust the production mode of today's society to avoid the problems of resource depletion and environmental degradation in the process of economic development and reasonably coordinate the transformation of man and nature. The metabolism of capitalism has led to the destruction of the natural environment and the surplus of poor people. How to explain the generation of poor people has become an important issue. Malthus regarded the excess population as natural and unalterable, and relief for them would only cause poverty on a larger scale. Capitalism also brought advanced science and technology. Liebig's chemical theory promoted the third agricultural revolution and greatly improved food productivity，so this proves that the development speed of productivity is likely to keep up with population growth. Marx believed that Malthus looked at the laws of population out of the real history and defended the rule of reaction. It was the inherent contradictions of capitalism that led to the excess population. Some contemporary scholars accuse Marx of being political in his criticism of Malthus and deliberately ignoring the limits of nature. This lacks evidence. Marx did not deny the limits of nature, but believed that the progress of industry can make people more and more powerful so that human beings can control nature to serve thenmselves. Marx did not set moral or realistic boundaries for the control of nature, and believed that the metabolism between man and nature should be adjusted reasonably and jointly to realize the free and comprehensive development of man. To some extent, this has the spirit of Prometheus, which is consistent with the modern enlightenment thought, but it does not disrespect objective laws. Human beings always have to face the realm of necessity, although this field will shrink with the expansion of productivity. Nor is it the so-called “anthropocentrism”. In the new socialist China, the in-depth study of Marx's natural thought is of great significance for us to understand and solve the ecological crisis and coordinate the relationship between man and nature. To solve population and environmental problems, we need to pay attention to the construction of ecological civilization and follow the development path of harmonious coexistence between man and nature.