12. The Essence of Spiritual Science and the Knowledge of the Transcendental World
But spiritual science stands - and this must be particularly emphasized - with regard to everything that has been said so far, completely on the ground of contemporary natural science. And there is - I cannot, of course, really mention the whole range of what would have to be mentioned now - there is nothing that can legitimately be brought forward in the indicated direction from the side of natural science that true, genuine spiritual science would contradict. Genuine, true spiritual science must fully admit that this thinking, as it confronts us in everyday life, that this feeling and willing, as it confronts us in everyday life, are the results of physical and material processes of the body and must therefore be extinguished the moment the body ceases to function at death. Everything that natural science has to say about this everyday life of the soul – and that alone is what it has to say – must also be a valid premise for true, genuine spiritual science.