Why did Darwin delay the publication of his theory?

In one of his essays, the evolutionary scientist Stephen Jay Gould tells why Darwin was late in announcing his theory of evolution, that it is not natural to delay the writing of his book The Origin of Species for almost twenty years, and that the justification for this is that he was seeking to verify the validity of his theory is false and unacceptable. Then he tells Gold the real reason for all this delay is fear, the fear of society's reaction to his theory and its implications. Darwin was "interested in philosophy and aware of what it entails. He knew that the main advantage that distinguished his theory of evolution from all other doctrines was its uncompromising character in philosophical materialism." He had "adopted something more ingenious than the idea of evolution itself, but was afraid to disclose it: philosophical materialism, the hypothesis that matter is the essence of the existence of things, and that all mental and spiritual phenomena are incidental. Nothing is more disturbing to the most established tradition of Western thought than to say that the mind, however complex and powerful it may be, is merely a by-product of the brain" Darwin "firmly applied in his notebooks the theory of material evolution to all the phenomena of life, including what he described as "the castle itself," that is, the human mind. If the mind had no real existence outside the brain, could God have been anything but an illusion invented by some sort of illusion? Darwin wrote in one of his books of transformation: "Love is from an organized divine influence, my materialist...Why does he think it is the secretion of the brain, and more wonderful than gravity is matter? This belief reached so far from heresy that Darwin avoided it in The Origin of Species (1859), in which he ventured only with a cryptic comment; that it "would shed light on man's origin and history", and only when he could not hide it for a longer time did he express his belief. - Dr. Hisham Azmi, The guided evolution between science and religion, I, 4, p. More: https://braheen.com/publications/التطور-الموجه-بين-العلم-والدين — Source: Published on Facebook's "Braheen Center" page https://www.facebook.com/braheen.org/posts/pfbid0uwimPZpG6R9TC3jNDfWNUK5ddybSAhp1cNAba8HJcSA4EQmV6NV5ZBonXJN1hKPtl