Does any one feel a doubt upon the point, as so stated?  If so, it will be upon him to show that Psychology, in its methodical pursuit, is a needless and superfluous employment of strength; that the problems of ethics, ontology, &c., can be solved without it—­a hard task indeed, so long as they are unsolved in any way.  I have no space for indulging in a dissertation on the value of methodical study and arrangement in the extension of our knowledge, as opposed to the promiscuous mingling of different kinds of facts, which is often required in practice, but repugnant to the increase of knowledge.  If you want to improve our acquaintance with the sense of touch, you accumulate and methodize all the experiences relating to touch; you compare them, see whether they are consistent or inconsistent, select the good, reject the bad, improve the statement of one by light borrowed from the others; you mark desiderata, experiments to be tried, or observations to be sought.  All that time, you refrain from wandering into other spheres of mental phenomena.  You make use of comparison with the rest of the senses, it may be, but you keep strictly to the points of analogy, where mutual lights are to be had.  This is the culture of knowledge as such, and is the best, the essential, preparation for practical questions involving the particular subject along with others.

To take an example from the question of the Will.  I do not object:  to the detaching and isolating of the problem of free-will, as a matter for discussion and debate; but I think that it can be handled to equal, if not greater advantage, in the systematic psychology of voluntary power.  Those that have never tried it in this last form have not obtained the best vantage-ground for overcoming the inevitable subtleties that invest it.

The great problem of External Perception has a psychological place, where its difficulties are very much attenuated, to say the least of it; and, however convenient it may be to treat it as a detached problem, we should carry with us into the discussion all the lights that we obtain while regarding it as it stands among the intellectual powers.

It is in systematic Psychology that we are most free to attend to the defining of terms (without which a professed science is mere moonshine), to the formulating of axioms and generalities, to the concatenating and taking stock of all the existing knowledge, and to the appraising of it at its real value.  If these things are neglected, there is nothing that I see to constitute a psychology at all.

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[DISCUSSIONS IN LOGIC PROPER.]