He failed to fathom the depths of the new psychology, which proved to him that, on that side as on the mathematical side, his power of thought was atrophied, if, indeed, it ever existed. Since he could not fathom the science, he could only ask the simplest of questions: Did the new psychology hold that the IvXn -- soul or mind -- was or was not a unit? He gathered from the books that the psychologists had, in a few cases, distinguished several personalities in the same mind, each conscious and constant, individual and exclusive. The fact seemed scarcely surprising, since it had been a habit of mind from earliest recorded time, and equally familiar to the last acquaintance who had taken a drug or caught a fever, or eaten a Welsh rarebit before bed; for surely no one could follow the action of a vivid dream, and still need to be told that the actors evoked by his mind were not himself, but quite unknown to all he had ever recognized as self. The new psychology went further, and seemed convinced that it had actually split personality not only into dualism, but also into complex groups, like telephonic centres and systems, that might be isolated and called up at will, and whose physical action might be occult in the sense of strangeness to any known form of force. Dualism seemed to have become as common as binary stars. Alternating personalities turned up constantly, even among one's friends. The facts seemed certain, or at least as certain as other facts; all they needed was explanation.
This was not the business of the searcher of ignorance, who felt himself in no way responsible for causes. To his mind, the compound IvXn took at once the form of a bicycle-rider, mechanically balancing himself by inhibiting all his inferior personalities, and sure to fall into the sub-conscious chaos below, if one of his inferior personalities got on top. The only absolute truth was the sub-conscious chaos below. which every one could feel when he sought it.
Whether the psychologists admitted it or not, mattered little to the student who, by the law of his profession, was engaged in studying his own mind. On him, the effect was surprising. He woke up with a shudder as though he had himself fallen off his bicycle. If his mind were really this sort of magnet, mechanically dispersing its lines of force when it went to sleep, and mechanically orienting them when it woke up -- which was normal, the dispersion or orientation? The mind, like the body, kept its unity unless it happened to lose balance, but the professor of physics, who slipped on a pavement and hurt himself, knew no more than an idiot what knocked him down, though he did know -- what the idiot could hardly do -- that his normal condition was idiocy, or want of balance, and that his sanity was unstable artifice. His normal thought was dispersion, sleep, dream, inconsequence; the simultaneous action of different thought-centres without central control. His artificial balance was acquired habit. He was an acrobat, with a dwarf on his back, crossing a chasm on a slack-rope, and commonly breaking his neck.
By that path of newest science, one saw no unity ahead -- nothing but a dissolving mind -- and the historian felt himself driven back on thought as one continuous Force, without Race, Sex, School, Country, or Church.
This has been always the fate of rigorous thinkers, and has always succeeded in making them famous, as it did Gibbon, Buckle, and Auguste Comte. Their method made what progress the science of history knew, which was little enough, but they did at last fix the law that, if history ever meant to correct the errors she made in detail, she must agree on a scale for the whole. Every local historian might defy this law till history ended, but its necessity would be the same for man as for space or time or force, and without it the historian would always remain a child in science.
Any schoolboy could see that man as a force must be measured by motion, from a fixed point. Psychology helped here by suggesting a unit -- the point of history when man held the highest idea of himself as a unit in a unified universe. Eight or ten years of study had led Adams to think he might use the century 1150-1250, expressed in Amiens Cathedral and the Works of Thomas Aquinas, as the unit from which he might measure motion down to his own time, without assuming anything as true or untrue, except relation. The movement might be studied at once in philosophy and mechanics.
Setting himself to the task, he began a volume which he mentally knew as "Mont-Saint-Michel and Chartres: a Study of Thirteenth-Century Unity."
From that point he proposed to fix a position for himself, which he could label: "The Education of Henry Adams: a Study of Twentieth-Century Multiplicity."
With the help of these two points of relation, he hoped to project his lines forward and backward indefinitely, subject to correction from any one who should know better. Thereupon, he sailed for home.