"J'ai lu livre de Mlle. Trotter. Dans la dedicace elle exhorte M. Locke à donner des démonstrations de morale. Je crois qu'il aurait eu de la peine à y reussir. L'art de démontrer n'est pas son fait. Je tiens que nous nous appercevons sans raisonnement de ce qui est juste et injuste, comme nous nous appercevons sans raison de quelques theoremes de Geometrie; mais il est tousjours bon de venir à la démonstration. Justice et injustice ne dependent seulement de la nature humaine, mais de la nature de la substance intelligente en général; et Mlle. Trotter remarque fort bien qu'elle vient de la nature de Dieu et n'est point arbitraire. La nature de Dieu est tousjours fondée en raison." Notwithstanding all this, the commentators of Locke appear, without exception, to ignore the _Defence_, and it was probably never much read outside the cultivated Salisbury circle. In this year, 1702, the health of Catharine Trotter began to give her uneasiness, and it was for this reason that she left Salisbury for a while. She was once more living in that city, however, from May 1703 to March 1704, making a special study of geography. "My strength," she writes to George Burnet, "is very much impaired, and God knows whether I shall ever retrieve it." Her thoughts turned again to the stage, and in the early months of 1703 she composed her fifth and last play, the tragedy of _The Revolution in Sweden_; "but it will not be ready for the stage," she says, "till next winter." Her interest in philosophy did not flag. She was gratified by some communications, through Burnet, with Leibnitz, and she would have liked to be the intermediary between Locke and some philosophical "gentlemen" on the Continent, probably Malebranche and Leibnitz, in a controversy. But this was hopeless, and she writes (March 16th, 1704):-- "Mr. Locke is unwilling to engage in controversy with the gentlemen you mention; for, I am informed, his infirmities have obliged him, for some time past, to desist from his serious studies, and only employ himself in lighter things, which serve to amuse and unbend the mind."