This law is announced with the air of a man who has made a great discovery, and who is entitled, in consequence, to be regarded both as an original thinker, and as a benefactor to the world.

"I believe," he says, "that I have discovered a grand fundamental law,"-- "the fundamental law of the development of the human mind;" ...

"the grand law which I have indicated in the first part of my system of Positive Politics, ...

where I have divulged, for the first time, the discovery of this law."[57] Now, what, it may be asked, is this marvellous discovery, which bids so fair both to immortalize its author and to enlighten the world?
It is stated briefly in the _first_, and illustrated at greater length in the _fourth_ and following volumes of his work.

The general outline of his theory is thus sketched: "That law consists in this,--that each one of our leading conceptions, every branch of our knowledge, passes successively through _three different theoretic states_: the state theological or fictitious, the state metaphysical or abstract, and the state scientific or positive.