The source of materialism?
I came across this recently, and found it interesting:
"We can even say that spiritual research reveals the source of humanity's materialistic attitude. In this day at age, there are indeed materialistically-minded souls who say either that it is impossible for us to speak of the spiritual world or that we should not worry about that world because our human capacity for knowledge is restricted to the sensory world. They also say that it is unscientific to speak of the life of in the spirit. Nowadays such people go by the genteel name of monists; we used is simply call them materialists. They deem themselves especially scientific when they completely denied the existence of a spiritual world war say that science has nothing to do with that world. Of course, when we state the truth about spiritual phenomena, we can scarcely expect to find support among dyed-in-the-wool monists. This truth remains the truth however, and it is fear, rather than any logical reasons or proof, that keeps souls imprisoned in materialism or monism. People do not recognize this fear as such and do not acknowledge it to themselves. Nonetheless, fear gives rise to the idea that it is unscientific to investigate the spiritual world. Anyone who understands the factors involved knows that materialistic organizations attract souls dominated by fear of the spiritual world. It is not pleasant tell people with that they are basically fearful souls and that they are simply cloaking their fear in a semblance of logic, as if they could prove that only the phenomena of the physical world are entitled to exist."
Rudolf Steiner. "First Steps in Inner Development." Hudson, NY: Anthroposophic Press, 1999. Pages 77-78. The lecture is titled: How does the soul discover its true being? (Kassel ? May 8th, 1914) Translated by Catherine Creeger.