"The atomists asked the mechanistic question, and gave a mechanistic answer. Their successors, until the Renaissance, were more interested in the teleological question, and thus led science up a blind alley. In regard to both questions alike, there is a limitation which is often ignored, both in popular thought and in philosophy. Neither question can be asked intelligibly about reality, as a whole (including God), but only about parts of it. ...The conception of purpose, therefore, is only applicable within reality, not to reality as a whole."