Now it was precisely the cases with autopsychic delusions, as well as with profound disorder of personality in general, that showed the brunt of the destructive paretic process in the frontal region. The other not-so-autopsychic cases did not show this frontal brunt, but were less markedly diseased at death and had a more diffuse process. Our genetic hint from paresis, therefore, inclines us to the conception that this disorder of the believing process is more frontal than parietal, more of the anterior association area than of the posterior association area of the brain. And if we can trust our intuitions so far, the perverted believing process is thus more a motor than a sensory process, more a disorder of expression than a disorder of impression, more a perversion of the WILL TO BELIEVE than a matter of the rationality of a particular credo. Again we may appear to burst through from an undergrowth of statistics into the clear field of truism. False beliefs are more practical than theoretical, more a matter of practical conduct than of passive experience, more a change of reagent than a reaction to change. The man on the street or even many a leading neurologist would perhaps accept this formula as his own. Certainly in general the least satisfactory of these chapters on the nature of delusions was the chapter on environmental effects,[3] and this perhaps because the results seemed so nearly negative. A further contribution to delusions of environmental nature was somewhat unexpectedly derived from a piece of work on the general mental symptomatology of general paresis.[4] Dichotomizing the paretics (all autopsied cases) into a group with substantial, i. e., encephalitic, atrophic or sclerotic lesions of the cortex and a group without such gross lesions or else with merely a leptomeningitis, I found the latter (or anatomically mild) group to be characterized by a set of symptoms which were all "contra-environmental," whereas the former (or anatomically severe) did not thus run counter to the environment. The conclusions of that paper, so far as they concern us now, are as follows:-- The "mild" cases showed a group of symptoms which might be termed contra-environmental, viz. allopsychic delusions, sicchasia (refusal of food), resistiveness, violence, destructiveness. The "severe" cases showed a group of symptoms of a quite different order, affecting personality either to a ruin of its mechanisms in confusion and incoherence, or to mental quietus involved in euphoria, exaltation, or expansiveness.