Ernst Haeckel

The soul is nothing but the sum of the functions of the brain, and therefore subject to the same laws as all other natural phenomena, including death and decay.

The whole of nature is a single, living, indivisible unity, governed by eternal, immutable laws, and there is no room for supernatural intervention.

The law of recapitulation is the most important general law of organic development, and provides the key to understanding the history of life on Earth, from the simplest single-celled organisms to the most complex multicellular forms.

The cell is the true elementary organism, the fundamental form of all living beings, and the starting point for all organic development, from the fertilization of the egg to the formation of the complete organism.

The human being is only a highly developed mammal, and in no way a special creation, but rather a product of the same natural laws that govern all other organisms, and therefore subject to the same processes of evolution and adaptation.

Monism is the rational connection of all phenomena in a single, all-encompassing world-view, which recognizes no supernatural forces or beings, and therefore provides a scientific basis for understanding the universe and our place within it.

The history of the development of the individual is a brief and rapid recapitulation of the history of the development of the species, and thus provides a powerful argument for the theory of evolution, demonstrating the close relationship between ontogeny and phylogeny.

The cell is the simplest form of life, the fundamental unit of all organisms, and the basis for all biological processes, from metabolism to reproduction, and therefore the key to understanding the nature of life itself.

The entire organic world is a single, continuous chain of development, from the simplest to the most complex forms, and this development is driven by natural selection, leading to the gradual adaptation of organisms to their environment.

The human being, like all other organisms, is a product of natural selection, and therefore subject to the same laws of evolution, including the struggle for existence and the survival of the fittest.

The soul is nothing but the sum of the functions of the brain, and therefore subject to the same laws as all other natural phenomena, including death and decay, and there is no evidence for its immortality.

The whole of nature is a single, living, indivisible unity, governed by eternal, immutable laws, and there is no room for supernatural intervention or divine creation.

The law of recapitulation is the most important general law of organic development, and provides the key to understanding the history of life on Earth, from the simplest single-celled organisms to the most complex multicellular forms, including humans.

The cell is the true elementary organism, the fundamental form of all living beings, and the starting point for all organic development, from the fertilization of the egg to the formation of the complete organism, and therefore the basis for all biological research.

The human being is only a highly developed mammal, and in no way a special creation, but rather a product of the same natural laws that govern all other organisms, and therefore subject to the same processes of evolution and adaptation, including the development of intelligence and consciousness.

Monism is the rational connection of all phenomena in a single, all-encompassing world-view, which recognizes no supernatural forces or beings, and therefore provides a scientific basis for understanding the universe and our place within it, without recourse to religious dogma.

The history of the development of the individual is a brief and rapid recapitulation of the history of the development of the species, and thus provides a powerful argument for the theory of evolution, demonstrating the close relationship between ontogeny and phylogeny, and the common ancestry of all living things.

The cell is the simplest form of life, the fundamental unit of all organisms, and the basis for all biological processes, from metabolism to reproduction, and therefore the key to understanding the nature of life itself, and its origins.

The entire organic world is a single, continuous chain of development, from the simplest to the most complex forms, and this development is driven by natural selection, leading to the gradual adaptation of organisms to their environment, and the diversification of life on Earth.

The human being, like all other organisms, is a product of natural selection, and therefore subject to the same laws of evolution, including the struggle for existence and the survival of the fittest, and there is no evidence for any special divine intervention in our creation.