The order of the dependence of the sciences is thus seen to be something more than the inverse order of generality and complexity. This of itself, as formulated by Comte, is a great truth, but there is a still deeper truth, viz., that each of the higher sciences is a product of the creative synthesis of all the sciences below it in the scale. Each science is thus distinct, though not independent. It is a new and different field of phenomena. Chemistry is not physics, but a science apart. Biology is not chemistry, nor is psychology, as Comte maintained, biology. Sociology is not psychology, still less biology. It is a science, new in two senses, viz., those of being newly created and newly discovered. It is the product of recompounding of the simpler  sciences. The sociological units are compounds of psychological units, but differ as much from their components as corrosive sublimate differs from chlorine or mercury. This principle also explains the relation of sociology to the special social sciences. It is not quite enough to say that it is a synthesis of them all. It is the new compound which their synthesis creates. It is not any of them and it is not all of them. It is that science which they spontaneously generate. It is a genetic product, the last term in the genesis of science. The special social sciences are the units of aggregation that organically combine to create sociology, but they lose their individuality as completely as do chemical units, and the resultant product is wholly unlike any of them and is of a higher order. All this is true of any of the complex sciences, but sociology, standing at the head of the entire series, is enriched by all the truths of nature and embraces all truth. It is the scientia scientiarum. (Ward 1919:90-1)
WARD, Lester. 1919. Pure sociology: a treatise on the origin and spontaneous development of society. New York: The Macmillan Company.