The ideal of the 11th/17th century physicists was to be able to explain all physical reality in terms of the movement of atoms. This idea was extended by people like Descartes who saw the human body itself as nothing but a machine. Chemists tried to study chemical reaction in this light and reduce chemistry to a form of physics, and biologists tried to reduce their science to simply chemical reactions and then finally to the movement of physical particles. The idea of reductionsm which is innate to modern science and which was only fortified by the tehory of evolution could be described as the reduction fo the spirit to the psyche, the psyche to biological activity, life to lifeless matter and lifeless matter to purely quantitative particles or bundles of energy whose movements can be measured and quantified.
