Ernst Haeckel

The soul is merely a sum of cerebral functions.

The struggle for existence is the driving force of evolution.

The 'soul' of man is nothing more than the sum of his brain functions.

The whole organic world is a single, continuous chain of development.

We must free ourselves from the shackles of dogma and superstition.

The law of substance is the fundamental law of the universe.

The beauty of nature is a reflection of its underlying laws.

The history of life on Earth is a grand epic of transformation.

Religion is a product of human imagination and fear.

The future of humanity lies in the embrace of scientific reason.

The human embryo, in its development, passes through stages resembling those of lower animals.

There is no supernatural intervention in the course of nature.

The study of nature is the highest form of worship.

The tree of life illustrates the common ancestry of all organisms.

The universe is a single, unified whole, governed by immutable laws.

We must educate the masses in the principles of evolution.

The human race is but a twig on the vast tree of life.

The concept of a personal God is incompatible with scientific understanding.

Nature is the only true teacher.

The development of the individual is a short, rapid sketch of the development of the species.