Hence, in regard to that most difficult question, what are the natural differences between the two sexes--a subject on which it is impossible in the present state of society to obtain complete and correct knowledge--while almost everybody dogmatizes upon it, almost all neglect and make light of the only means by which any partial insight can be obtained into it. This is, an analytic study of the most important department of psychology, the laws of the influence of circumstances on character. For, however great and apparently ineradicable the moral and intellectual differences between men and women might be, the evidence of their being natural differences could only be negative. Those only could be inferred to be natural which could not possibly be artificial--the residuum, after deducting every characteristic of either sex which can admit of being explained from education or external circumstances. The profoundest knowledge of the laws of the formation of character is indispensable to entitle any one to affirm even that there is any difference, much more what the difference is, between the two sexes considered as moral and rational beings; and since no one, as yet, has that knowledge, (for there is hardly any subject which, in proportion to its importance, has been so little studied), no one is thus far entitled to any positive opinion on the subject. Conjectures are all that can at present be made; conjectures more or less probable, according as more or less authorized by such knowledge as we yet have of the laws of psychology, as applied to the formation of character.