Arne Dekke Eide Næss (/ˈɑːrnə ˈnɛs/, AR-nə NESS; Urban East Norwegian: [ˈɑ̂ːɳə ˈdɛ̂kːə ˈæ̂ɪdə ˈnɛsː]; 27 January 1912 – 12 January 2009) was a Norwegian philosopher who coined the term "deep ecology", an important intellectual and inspirational figure within the environmental movement of the late twentieth century, and a prolific writer on many other philosophical issues.

[4] Næss cited Rachel Carson's 1962 book Silent Spring as being a key influence in his vision of deep ecology.

Næss believed that the environmental crisis of the twentieth century had arisen due to certain unspoken philosophical presuppositions and attitudes within modern western developed societies which remained unacknowledged.

In contrast to the prevailing utilitarian pragmatism of western businesses and governments, he advocated that a true understanding of nature would give rise to a point of view that appreciates the value of biological diversity, understanding that each living thing is dependent on the existence of other creatures in the complex web of interrelationships that is the natural world.

[9] In 1970, together with a large number of protesters, he chained himself to rocks in front of Mardalsfossen, a waterfall in a Norwegian fjord, and refused to descend until plans to build a dam were dropped.

[1] Næss's book Erkenntnis und wissenschaftliches Verhalten (1936) anticipated many themes familiar in post-war analytic philosophy.

[20] Næss developed a simplified, practical textbook embodying these advantages, entitled Communication and Argument: Elements of Applied Semantics (1966),[21] which became a valued introduction to this pragmatics or "language logic", and was used over many decades as a sine qua non for the preparatory examination at the University of Oslo, later known as examen philosophicum ("exphil").

[24] Næss argued for adhering to the following principles to make discussions as fruitful and pleasant as possible:[24][9] For many years these points were part of a compulsory course in philosophy (examen philosophicum) taught in Norwegian universities.

[further explanation needed] According to one writer, Næss defined the ethical consequences of self-realization as: If one does not know how the outcomes of one's actions will affect other beings, one should not act.