Introduction.

...distinguish from one another. The strokes on the left express the genus the general category or "kind", while those on the right express the species the specific type or sub-category to which the designated concept belongs. This attempt by Wilkins to find suitable characters particularly pleased Leibniz; he emphasizes Wilkins’ achievement again and again; how far he surpassed it, we shall see later. —

The correspondence between Leibniz and Oldenburg Henry Oldenburg was the Secretary of the Royal Society in London and a central figure in the 17th-century scientific "Republic of Letters." until mid-October 1671 primarily concerns the New Physical Hypothesis original title: Hypothesis physica nova published by Leibniz in that same year, the first part of which, Theory of Concrete Motion original title: Theoria motus concreti, Leibniz had dedicated to the Royal Society in London; other matters were mentioned only incidentally. Since mid-October 1671, the correspondence rested; it is likely that preparations for the journey to Paris, which Leibniz began on March 19, 1672, fully occupied his activities. From January 11 to the beginning of March 1673, Leibniz made a detour to London as part of the delegation from the Elector of Mainz. In the conversations he had with Oldenburg and the chemist Boyle Robert Boyle, the natural philosopher famous for Boyle’s Law during this time, the characteristic Leibniz's "Universal Characteristic," an early vision of symbolic logic where symbols represent thoughts was also discussed, as he himself reports in the remark shared above in his copy of Dalgarno’s Art of Signs original title: Ars signorum. After his return from London, Leibniz pursued mathematical studies with the greatest zeal. Therefore, in his correspondence with Oldenburg, other topics are rarely mentioned. In the letter dated Paris, April 16/26, 1673, it says:

I should wish for Wilkins' characters to appear in Latin as soon as possible; for it has seemed to me a most useful work. original Latin: "Optem Wilkinsii Characterem latinum prodire quam primum; visum enim est mihi opus utilissimum."

Leibniz discusses the Characteristic Combinatorics the study of how simple concepts combine to form complex ones in more detail in the letter from Paris, dated December 28, 1675:

We seem to ourselves to think many things (confusedly, of course) which are nevertheless contradictory original Latin: "implicant," here meaning logically impossible or self-contradictory: for example, the Number of all numbers. The notions of the Infinite, and the Minimum, and the Maximum, and the Most Perfect, and even of "All-ness" itself, ought to be deeply suspect to us. Nor should these notions be trusted until they are weighed against that criterion, original Latin: "Multa videmur nobis Cogitare (confuse scilicet) quae tamen implicant: exempli gratia, Numerus omnium numerorum. Valde suspectum esse debet nobis Notio Infiniti, et Minimi, et Maximi, et Perfectissimi, et ipsius Omnitatis. Neque fidendum his notionibus, antequam ad illud Criterion exigantur,"