He enquired into classical and modern philosophy in his search for an adequate theoretical overview[3] and ended by adopting an Aristotlean teleological theory of entelechy.

This was contrary to his expectation that each cell would develop into the corresponding half of the animal, a prediction based on Wilhelm Roux's earlier work with frog embryos.

This seemed to be an important refutation of both early preformation ideas and the later mosaic theory of Wilhelm Roux, and was to be subject to much discussion in the ensuing years.

Driesch's results were confirmed with greater precision, and the experiments extended, by Sven Hörstadius who showed that conclusions of equivalence between sea urchin embryonic cells were an over-simplification.

Driesch, believing that his results compromised contemporary mechanistic theories of ontogeny, instead proposed that the autonomy of life that he deduced from this persistence of embryological development despite interferences was due to what he called entelechy, a term borrowed from Aristotle's philosophy to indicate a life force which he conceived of as psychoid or "mind-like", that is; non-spatial, intensive, and qualitative rather than spatial, extensive, and quantitative.

Driesch was awarded the chair of natural theology at the University of Aberdeen, where he delivered the Gifford Lectures in 1906 and 1908 on The Science and Philosophy of the Organism - the first comprehensive presentation of his ideas.

In 1933 he was removed from his Leipzig chair and prematurely placed in emeritus status by the Nazi administration,[5] the first non-Jewish academic to be thus expelled, because of his pacifism and open hostility to Nazism.