The opinion was written by Sir Philip Yorke (then the Attorney General) and Charles Talbot (then the Solicitor General), each of whom would later rise to the rank of Lord Chancellor as Lord Hardwicke and Lord Talbot respectively. As they wrote the opinion in their capacity as law officers of the Crown (as opposed to opinions of counsel produced for private clients), the opinion was assumed to represent a neutral statement of the law as it stood.
They summarised the following.
We are of opinion, that a slave coming from the West-Indies to Great-Britain or Ireland, with or without his master, doth not become free, and that his master's property or right in him is not thereby determined or varied; and that baptism doth not bestow freedom on him, or make any alteration in his temporal condition in these kingdoms. We are also of opinion, that his master may legally compel him to return again to the plantations.
The opinion cited no authorities, and set out no legal rationale for the views expressed in it, but it was widely published and relied upon. The opinion was largely accepted in England as a definitive statement of the law for nearly 40 years. Curiously, the opinion made no reference either to the abolition of trade in serfs of 1102 by the Council of Westminster, or to the decision in In the matter of Cartwright, 11 Elizabeth; 2 Rushworth's Coll 468 (1569), a case often cited as authority for the statement "that England has too pure an air for a slave to breathe in. Nor did it refer to the first edition of Sir William Blackstone's hugely influential work, Commentaries on the Laws of England, which asserted that slaves were free when they came to England, or indeed the two decisions of Lord Holt (Chamberlain v Harvey and Smith v Gould) which led to so much of the controversy.
Ultimately slavery would be abolished by statute in both England and throughout the colonies pursuant to the Slave Trade Act 1807 and the Slavery Abolition Act 1833, and the status and effect of the Yorke-Talbot slavery opinion was reduced to that of a footnote in history.