Francis Bacon struck a note which still reverberates: that knowledge is power. He saw a relationship between our knowledge of the external world, and our ability to submit the laws of its action to our own ends; the realization of the relationship was to lead, in effect, to a revision of those laws. But in Bacon's opinion, one of the obstacles which impedes our progress is that "the human mind is of its own nature prone to suppose the existence of more order and regularity in the world than it finds." ¹ We must rather abandon the "pernicious and inveterate habit of dwelling on abstractions," ² and fix our attention instead upon the evidence of the senses.