By Sam Vaknin
Author of "Malignant Self-love: Narcissism Revisited"

All psychological theories can be classified by one or more of these dichotomies (pairs):

Dualism vs. Monism

The belief that the mind and the body are two separate entities (though in constant interaction via various mechanisms and pathways); OR

The belief that the mind is nothing but an emergent phenomenon or a manifestation of and emanation from or a mislabelling physiological processes and qualities and, therefore, that psychology should be a branch of neuroscience or medicine (medicalization of psychology).

Innate vs. Stimuli-driven

The belief that all psychological traits and processes are innate and autonomous; OR

The belief that psychological processes are triggered by and psychological traits are shaped and conditioned by stimuli emanating from the environment.

Nature vs. Nurture

The belief that genes and, more comprehensively, evolution determine one’s psychological make-up and modus operandi; OR

The belief that one’s psychology is decided by one’s upbringing, human milieu, and personal history.

Reductionist vs. Holistic

The belief that psychology can be analytically reduced to a set of interacting, distinct, atom-like components or constructs; OR

The belief that one’s psychology is the complex, irreducible outcome of shape-shifting network of ceaseless interactions and the synergy of extensive and intensive qualities, parameters of action and boundary conditions.

Fixed vs. Plastic (Childhood vs. Lifespan or Determined vs. Mutable)

The belief that, at a certain age, one’s psychology becomes an immutable fixture, subject only to minor, almost imperceptible modifications; OR

The belief that one’s brain is plastic and reprogrammable from cradle to grave and that, therefore, one’s psychological settings and proceedings are constantly evolving and changing throughout the lifespan.

Static vs. Dynamic (Objective vs. Subjective)

The belief that psychological reactions and processes are rigid and set, allowing for well-demarcated diagnoses based on sharply-delineated clinical entities which are subject to the scientific method; OR

The belief that psychology is a narrative, fuzzy, impressionistic, ever-evolving, and somewhat “artistic”. Diagnosis and treatment require human contact and interaction, mostly subjective and emotional.

Process vs. Behavior

The belief that psychological processes constantly occur in the mind and underlie behaviors, cognitions, and choices and that they can be subject to meaningful and informed introspection; OR

The belief that, since we can never, in principle observe or measure inner processes in the mind (the intersubjective agreement is not falsifiable), we should only monitor, observe, and analyze behaviors.

Categorical vs. Dimensional

The belief that human behaviors, both normal and pathological (aberrant), can be categorized, distinguished, and demarcated with a minimum of ambiguity and overlap; OR

The belief that human behaviors constitute a spectrum and can be described only using interacting multi-purpose dimensions.

Statistical-Normal vs. Descriptive-Spectrum

The belief that human behaviors cluster around a mean or average which constitutes “normalcy”; OR

The belief that all human behaviors, preferences, drives, urges, traits, and orientations are “normal” (though they may be socially unacceptable or even illegal) and are part of a spectrum, even when there is only anecdotal evidence for their existence.

Analogous vs. Standalone

The belief that modelling human psychology by using analogies to various technologies provides real, testable insights into the human mind; OR

The belief that the human mind and its products are sui generis and cannot be studied by analogy. Getting to know the mind requires its own models and theories, independent of models and theories in other fields of science and knowledge.

Occult (Multipartite) vs. Overt (Monolithic)

The belief that the human mind is comprised of several interacting parts, some of which are accessible trivially while the awareness to and knowledge of other parts require special efforts and knowledge; OR

The belief that the mind is a monolithic, indivisible “black box”, which can be observed and analysed only via its effects on the world and interactions with reality.

Mechanical vs. Stochastic/Emergent

The belief that the mind is a machine which, like other machines, is subject to the laws of Nature and can be deciphered and contextualized objectively and even mathematically; OR

The belief that the mind is a cloud, the emergent outcome of numerous intertwined and fuzzy processes in constantly self-assembling and redundant networks and that the underlying math is stochastic rather than deterministic.

Theoretical vs. Experimental

The belief that psychology is a philosophy of the mind, not a rigorous science and that, consequently, it cannot be falsified and the results of its experiments cannot be repeated or replicated.

The belief that psychology is a science whose theories can yield falsifiable predictions and whose experiments are repeatable and replicable.