But (it is said) there is anatomical evidence of the superior mental capacityof men compared with women: they have a larger brain. I reply, that in thefirst place the fact itself is doubtful. It is by no means established thatthe brain of a woman is smaller than that of a man. If it is inferred merelybecause a woman's bodily frame generally is of less dimensions than a man's,this criterion would lead to strange consequences. A tall and large-bonedman must on this showing be wonderfully superior in intelligence to a smallman, and an elephant or a whale must prodigiously excel mankind. The sizeof the brain in human beings, anatomists say, varies much less than the sizeof the body, or even of the head, and the one cannot be at all inferred fromthe other. It is certain that some women have as large a brain as any man.
It is within my knowledge that a man who had weighed many human brains, saidthat the heaviest he knew of, heavier even than Cuvier's (the heaviest previouslyrecorded), was that of a woman. Next, I must observe that the precise relationwhich exists between the brain and the intellectual powers is not yet wellunderstood, but is a subject of great dispute. That there is a very closerelation we cannot doubt. The brain is certainly the material organ of thoughtand feeling: and (making abstraction of the great unsettled controversy respectingthe appropriation of different parts of the brain to different mental faculties)I admit that it would be an anomaly, and an exception to all we know of thegeneral laws of life and organisation, if the size of the organ were whollyindifferent to the function; if no accession of power were derived from thegreat magnitude of the instrument. But the exception and the anomaly wouldbe fully as great if the organ exercised influence by its magnitude only.
In all the more delicate operations of nature -- of which those of the animatedcreation are the most delicate, and those of the nervous system by far themost delicate of these -- differences in the effect depend as much on differencesof quality in the physical agents, as on their quantity: and if the qualityof an instrument is to be tested by the nicety and delicacy of the work itcan do, the indications point to a greater average fineness of quality inthe brain and nervous system of women than of men. Dismissing abstract differenceof quality, a thing difficult to verify, the efficiency of an organ is knownto depend not solely on its size but on its activity: and of this we havean approximate measure in the energy with which the blood circulates throughit, both the stimulus and the reparative force being mainly dependent onthe circulation. It would not be surprising -- it is indeed an hypothesiswhich accords well with the differences actually observed between the mentaloperations of the two sexes -- if men on the average should have the advantagein the size of the brain, and women in activity of cerebral circulation.
The results which conjecture, founded on analogy, would lead us to expectfrom this difference of organisation, would correspond to some of those whichwe most commonly see. In the first place, the mental operations of men mightbe expected to be slower. They would neither be so prompt as women in thinking,nor so quick to feel. Large bodies take more time to get into full action.
On the other hand, when once got thoroughly into play, men's brain wouldbear more work. It would be more persistent in the line first taken; it wouldhave more difficulty in changing from one mode of action to another, but,in the one thing it was doing, it could go on longer without loss of poweror sense of fatigue. And do we not find that the things in which men mostexcel women are those which require most plodding and long hammering at asingle thought, while women do best what must be done rapidly? A woman'sbrain is sooner fatigued, sooner exhausted; but given the degree of exhaustion,we should expect to find that it would recover itself sooner. I repeat thatthis speculation is entirely hypothetical; it pretends to no more than tosuggest a line of inquiry. I have before repudiated the notion of its beingyet certainly known that there is any natural difference at all in the averagestrength or direction of the mental capacities of the two sexes, much lesswhat that difference is. Nor is it possible that this should be known, solong as the psychological laws of the formation of character have been solittle studied, even in a general way, and in the particular case never scientificallyapplied at all; so long as the most obvious external causes of differenceof character are habitually disregarded -- left unnoticed by the observer,and looked down upon with a kind of supercilious contempt by the prevalentschools both of natural history and of mental philosophy: who, whether theylook for the source of what mainly distinguishes human beings from one another,in the world of matter or in that of spirit, agree in running down thosewho prefer to explain these differences by the different relations of humanbeings to society and life.
