It was not the question of the natural rights of the negro, the prejudice of color, nor of the ruinous improvidence of the system of slavery, that controlled the decision in Mr. Jefferson's mind, as to the methods by which the system should be terminated. On these points, he was as radical as the extremest abolitionist; but he could not satisfy himself as to the mental capacity of the negro--whether he had the full complement of human capabilities, and the qualifications for equality of citizenship with the white man; for he saw that emancipation, without expatriation, meant nothing else than giving the black man all the rights of citizenship. The theory that the negro is a decaudalized ape, a progressing chimpanzee, is an invention of the last forty years, and contemporaneous with the discovery that the Bible sanctions slavery. He was, on the whole, inclined to the opinion that they were an inferior race of beings, and that their residence, in a state of freedom, among white men was incompatible with the happiness of both. He thought they had better be emancipated, and sent out of the country. He therefore took up with the colonization scheme long before the Colonization Society was founded. He did not feel sure on this point. With his practical mind, he could not see how a half million of slaves could be sent out of the country, even if they were voluntarily liberated;[8] where they should be sent to, or how unwilling masters could be compelled to liberate their slaves. While, therefore, he did not favor immediate emancipation, he was zealous for no other scheme. Bishop Gregoire, of Paris, felt deeply hurt at Mr. Jefferson's low estimate of the negro's mental capacity, and wrote to him a sharp letter on the subject. Later, the Bishop sent a copy of his own book on the Literature of Negroes.[9] Acknowledging the receipt of the Bishop's book, Mr. Jefferson says: