The objective of the paper is to present philosophical positions arguing the unity of nature: from the pantheistic doctrine of the Stoics and the version of pantheism proposed by G. Bruno and B. Spinoza, through the Leibniz concept which assumes that every element of nature is spiritual and capable of intentional actions, to contemporary doctrines. One of the concepts – the “deep ecology” of A. Naess, emphasizes the need for the subjective treatment of every element of nature – people, animals and plants; it postulates the specific equality of all species. The assumptions of eco-philosophy are perfectly in line with the findings of contemporary nature researchers proving that the bonds between individual elements of a given ecosystem are de...