On the other hand, the pituitary seems to be related to preservation of the memory deposit.  In conditions of disease of the pituitary, loss of memory for past experiences is more marked.  As regards recent experiences, they are better held, although in a sort of subconscious manner, recoverable when the condition improves or is cured.  But the greatest difference between the thyroid and pituitary effects upon memory exists as regards material:  the thyroid memory applies particularly to perception and percepts, the pituitary to conception (reading, studying, thinking) and concepts.

Judgment is another mental process that often intervenes between sensation and the energy-reaction.  It involves memory and association of experiences.  Behind it is an attitude as much as there is in an emotion or the arousing of an instinct.  Beliefs and reasonings are complex judgments.  They form the units of the intellectual process.

There is an element of speed in judgment on reasoning as in perception and memory.  And as in the latter, the thyroid determines the velocity.  Quick thinking, as we call it, means good thyroid action, and slow thinking deficient thyroid action.  The other element in judgment, accuracy, is influenced by the ante-pituitary.  During adolescence there is physical growth which consumes most of the secretion of the ante-pituitary.  After adolescence, after the early twenties, when physical growth has ceased, the ante-pituitary secretion sensitizes the cells of the brain to mental growth.  The reaction potential of the ante-pituitary, that is its inherent, latent ability to supply a maximum of its endocrine for the nerve cells of the frontal lobes, is the best-known chemical determinant of intellectual genius.  It makes for the greatest co-ordination of experience, knowledge, information, tastes and problems into one harmonious whole.  And curiously, not only does it cause a fusion of intellectual material:  it creates a desire for and a love of such material.

We should expect to find extraordinarily well-developed ante-pituitary action among eminent philosophers and men of science, and we do.  Adequate action of it is present throughout the range of normals who evidence sufficiently ripened judgment as they progress through life.  The ability to profit by experience, and to make more and more accurate judgments as one grows older implies at least a maximum efficiency of it.  This maturation is not at all universal.  Even after middle age, after forty and fifty years of reasoning, some individuals retain the juvenile mind of their youth.  Like the Bourbons, they have learned nothing and forgotten nothing.  Their ante-pituitary insufficiency often coupled with a post-pituitary excess, and other instabilities and disequilibriums in the endocrine system, render them immature morons, compared with what might be expected of them for their years.  They are the people who are old enough to know better.  For the same reasons, inhibition and emotional control are poor in them.