Do the Marxist of today still subscribe to the notion....?

Do the Marxist of today still subscribe to the notion that all existence is matter in motion, that nothing exists in the universe except matter in motion? Is it true that thoughts are the secretions of the brain much of the same way gastric juice is the secretion of the stomach? Where do thought come from? If man is all matter, and his brain secretes thought, how come the development of human mind in relation to ideas?