When Adam Lanza, the young man who went on a shooting spree, killing about 20 children and a handful of adults at a Connecticut elementary school, was being tried in the court of public opinion, most commentators simultaneously diagnosed and judged the mass murderer: Lanza, we were assured, was both mentally ill and evil.  But as I noted at the time, the language of “illness” and that of “evil,” belonging as they do to entirely separate modes of thought, are mutually incompatible.

We could not, at one and the same time, describe Lanza as both ill and evil. The reason for this is straightforward enough: if Lanza’s actions were the function of an illness, then he could no more be responsible for them than could a chemo patient be held responsible for his reaction to the nausea that it induces.

In fact, if anything, the patient in such circumstances would deserve our pity.  Similarly, if we insist on explaining Lanza’a acts solely in terms of a “sickness,” then he too is entitled to our sympathy.  Had Lanza not killed himself, then, he would no more have deserved punishment, or even blame, than would any other “sick” person deserve condemnation.

Situations of this kind should force us to consider, or reconsider, the nature of the relationship between morality and psychology.

“Psychology” literally means the study of the soul.  The first “psychologists” were such ancient Greek thinkers as Plato and Aristotle who were what today would be called (confusingly) “moral psychologists,” for they were interested in determining how human beings acquired virtue and vice.  Aristotle, for instance, had famously observed that since no one is born either virtuous or vicious, since virtue and vice consist in habits that we imbibe upon emulating those by whom we’re surrounded, a person’s upbringing makes practically all of the difference in the world as far as his character formation is concerned.

Yet modern psychology, seeking to assimilate itself to the natural sciences (which also have their roots in the ancient Greek study of “natural philosophy”), tends to reject the teleological orientation of Greek thought in favor of the resolutely non-purposeful, mechanistic suppositions underwriting the thrust of modern science.

What this means is that the idiom of modern psychology encompasses the very same kinds of terms as those found in all of the sciences.  Human beings, for instance, are fundamentally no different from any other inhabitant of the spatial-temporal world in that their “behavior” is “caused” by “mechanisms” or “processes” that, in turn, are governed by the laws determining all bodies.

Yet psychology also consists in terms that are peculiar to its discipline: mental states, conditions, disorders, impulses, psychoses, maladjustments, health, illness, stimuli, therapy, rehabilitation, etc. are just some of the characteristic concepts composing the universe of psychological discourse.

Whether psychology can legitimately be assimilated to the language of the natural sciences we can leave to one side.  The point here is that as long as psychologists insist upon regarding human beings as, essentially, objects that differ in degree, but not kind, from all other objects, then it supplies us with a vocabulary from which the terms of morality are, and can only be, conspicuously absent.

Human beings considered under the aspect of morality are persons or subjects, not objects.  Persons do not behave; they act.  As the philosopher Michael Oakeshott says, the agents occupying the moral world engage in “conduct.” Conduct, though, isn’t caused; it is chosen by self-governing consciousnesses in accordance with, not conditions, but reasons. The vocabulary of morality is comprised of the terms of right and wrong; good, bad, evil; virtue and vice; duties and rights; free will; responsibility; justice; and so on.

From the perspective of morality, then, we are agents who are determined by nothing save our own decisions, choices for which we are justly praised or blamed, rewarded or punished.

It should be clear that psychology and morality are mutually incommensurable modes of thought: it is impossible for the terms of the one to ever be translated into those of the other.    Yet just because the modes of psychology and morality are incommensurable doesn’t mean that they are mutually antagonistic:  there can be commerce between the two.     

The reason for this isn’t all that difficult to grasp.  Psychology is explanatory while morality is justificatory—and between explanation and justification there is all of the difference.

If psychology is a threat to morality because of its tendency to reduce humans to objects determined by the same universal laws of space and time (like causation) determining all other material objects, then biology, chemistry, and physics must be deemed a threat to morality as well, for they too permit no room within their respective frames of reference for the concepts of morality.  After all, such prominent scientific theories as that propounded by Darwin were, and in some quarters, remain rejected precisely because it had been feared that they imperil morality.

It is at this juncture that we must distinguish science from scientism, psychology from psychologism.

Psychologism is a variant of scientism, the transformation of science into an intellectual hegemon, an imperialistic creed assuming a monopoly over all human utterances.  From the standpoint of scientism, no language that is not the language of science is a respectable language at all.   Psychologism, then, is the perspective that all human actions, feelings, thoughts, and words can and should be accounted for in the terms of the psychologist.   Obviously, this is not at all compatible with the moral universe, a “kingdom of ends,” as Kant described it.

Modern psychology, like any other discipline, is a work in progress, and psychology especially remains in very much a confused intellectual state.  For the time being, however, it doesn’t seem that even if its pretensions to science are accepted, that it undermines morality.

Psychologism, like the scientism of which it is a variant, is the danger from which we must guard the moral life.