In the epistles, he professes to be working on a plan.

The first expounds his favourite theory (also treated in the essay) of a "ruling passion." Each man has such a passion, if only you can find it, which explains the apparent inconsistency of his conduct.

This theory, which has exposed him to a charge of fatalism (especially from people who did not very well know what fatalism means), is sufficiently striking for his purpose; but it rather turns up at intervals than really binds the epistle into a whole.

But the arrangement of his portrait gallery is really unsystematic; the affectation of system is rather in the way.

The most striking characters in the essay on women were inserted (whenever composed) some time after its first appearance, and the construction is too loose to make any interruption of the argument perceptible.