Here is a link to a recent essay by John Finnis and Robert George. The essay is a response to a paper by Aaron Tang. In a recent paper, Tang argued that pro-life advocates (such as Finnis and George) have inaccurately described the historical record about the number of states that prohibited abortion in 1868 (the effective date of the 14th Amendment).
In their new essay, Finnis and George explain that Tang’s essay “is conceptually even more confused and historically even more error-strewn” than the deeply flawed historical work of Cyril Means, whose work was relied upon by Justice Blackmun in Roe v. Wade.