(2) Co-existence, as _Man is mortal_; that is, _the being subject to death coinheres with the qualities on account of which we call certain objects men_.

(3) Succession, as _Night follows day_.
(4) Causation (a particular kind of Succession), as _Water rusts iron_.
(5) Resemblance, as _The colour of this geranium is like that of a soldier's coat_, or _A = B_.
On comparing this list of real predications with the list of logical relations given above (chap.i.Sec.5 (a)), it will be seen that the two differ only in this, that I have there omitted simple Existence.

Nothing simply exists, unrelated either in Nature or in knowledge.

Such a proposition as _The bison exists_ may, no doubt, be used in Logic (subject to interpretation) for the sake of custom or for the sake of brevity; but it means that some specimens are still to be found in N.
America, or in Zoological gardens.
Controversy as to the Import of Propositions really turns upon a difference of opinion as to the scope of Logic and the foundations of knowledge.

Mill was dissatisfied with the "congruity" of concepts as the basis of a judgment.