when published many years later. I may mention that among the
alterations which my father made in revising his _Elements_ for the
third edition, several were founded on criticisms elicited by these
conversations; and in particular he modified his opinions (though not to
the extent of our new speculations) on both the points to which I
have adverted.

When we had enough of political economy, we took up the syllogistic
logic in the same manner, Grote now joining us. Our first text-book was
Aldrich, but being disgusted with its superficiality, we reprinted one
of the most finished among the many manuals of the school logic, which
my father, a great collector of such books, possessed, the _Manuductio
ad Logicam_ of the Jesuit Du Trieu. After finishing this, we took up
Whately's _Logic_, then first republished from the _Encyclopedia
Metropolitana_, and finally the _Computatio sive Logica_ of Hobbes.
These books, dealt with in our manner, afforded a high range for
original metaphysical speculation: and most of what has been done in the
First Book of my _System of Logic_, to rationalize and correct the
principles and distinctions of the school logicians, and to improve the
theory of the Import of Propositions, had its origin in these
discussions; Graham and I originating most of the novelties, while Grote
and others furnished an excellent tribunal or test. From this time I
formed the project of writing a book on Logic, though on a much humbler
scale than the one I ultimately executed.

Having done with Logic, we launched into Analytic Psychology, and having
chosen Hartley for our text-book, we raised Priestley's edition to an
extravagant price by searching through London to furnish each of us with
a copy. When we had finished Hartley, we suspended our meetings; but my
father's _Analysis of the Mind_ being published soon after, we