Mr. Sewall was chosen one of the Assistants in 1684, '5, and '6, when the Colony charter was annulled, and the ancient government was superseded by a President and Council. In 1688, during the oppressive administration of Sir Edmund Andros, when the titles of many to their lands, and of his among others, were questioned and in danger of being forfeited, he made a voyage to England. But on his return, in 1689, Sir Edmund having withdrawn from the country, and the old Charter government having been revived, he resumed his seat at the Board of Assistants. In the Provincial charter, granted in 1692, he was nominated to be of the Council; and afterwards, without interruption, was annually chosen and sat at the Board until 1725, when being elected, he declined serving; having survived more than seven years all who were appointed with him to that office in the charter.
As one of the Assistants under the Colonial charter, Mr. Sewall was also _ex officio_ a Judge of the Supreme Court. Soon after the arrival of the Provincial charter in May, 1692, but before any courts of justice had been established and organized under it, he was appointed one of the Judges of a Special Court of Oyer and Terminer for the trial of persons charged with witchcraft, William Stoughton, Esq., being Chief-Justice. It is well known, that at that time there was a general persuasion, not only in New England, but in the mother country, and throughout Europe, of the reality of those impious compacts with Satan, into which persons guilty of witchcraft were supposed to have entered, and of that diabolical power or influence, by which they were believed to act.[A] This court especially was under the delusion; and consequently _nineteen_ persons of the many who were indicted and arraigned before it at Salem for this crime, were, at different times, tried, condemned, and, in pursuance of its sentence, executed. In this unhappy affair, the Judges proceeded with great caution, asking advice of some of the wisest and best men in the community, and having the countenance of rulers, ministers, and in general of all classes of men. But the delusion was soon made manifest. Judge Sewall in particular was convinced of his error, in the part which he had taken in the court of trials; and often discovered deep regret and humiliation on account of it. He notes particularly in his Journal of Dec. 24, 1696, on occasion of his son Samuel's reciting to him in Latin a portion of Matthew xii, "the 7th verse did awfully bring to mind the Salem Tragedie." And at a public Fast, Jan. 14, 1697, in the order for which there was some reference to the doings of that court of Oyer and Terminer, and when he was under much affliction on account of the death of an infant daughter and other troubles and crosses, he presented to Rev. Samuel Willard, his minister, a "bill," which was read in the worshipping assembly; (he standing up while Mr. Willard read it, and bowing in token of assent when he had done;) in which, while with much delicacy he appears to have studiously avoided saying any thing that might seem to implicate the other judges, he acknowledged his own guilt in the decisions of that court, asked the pardon of it both of God and man, and deprecated the Divine judgments on account of his sin or the sin of any other person, upon himself, his family, or the land.