Beasts and birds all have a tendency to be clean and pure, and for man it is necessary that he should develop this tendency. It helps, not only on the spiritual path, but also in the development of the mind. To the artist in his art, to the scientist in his science, in all aspects of life it gives happiness. When man neglects it, that does not mean that he does not like it, it is only out of negligence that he overlooks things that are of the first importance.