From the book reviews: This is the first complete English edition of Saccheri's Euclides vindicatus of 1733, and, with 55 pages of introduction, 99 pages of notes, 11 pages of bibliography, the definitive one. ... The material in the introduction and the notes is of great interest to both historians of mathematics and to mathematicians ... . (Victor V. Pambuccian, zbMATH, Vol. 1303, 2015)