Welcome to the Century of Neuroscience, the Century of the Brain – Part II: Trending – Christian Monistic Views

In the second installment of this series, we will briefly survey Christian monism, the view that humans are made up of physical matter and do not consist of an additional substance/essence or non-material life force/principle, traditionally referred to as the “soul.” Christian monists claim that a nuanced view of monism (1) is consistent with the central doctrines/teachings of orthodox Christianity, (2) takes discoveries in the neurosciences more seriously than dualism does, and (3) can avoid the extreme reductionism often embraced by non-theistic monism.

The beginnings of a Christian monistic view of human nature predate modern neuroscience. Biblical scholars and theologians of the 19^th and especially the 20^th century began to consider more monistic views as they revisited Christian Scriptures. Many argued that the Hebraic Old Testament, in particular, was better interpreted as being at least holistic, if not monistic, in its view of human nature. The New Testament documents, while appearing more congruent with a dualistic interpretation than the Old Testament, also came under scrutiny.

With respect to the Old Testament, monistically leaning scholars argued that the Hebrew word, nephesh, translated in the KJV of the Bible as “soul,” does not have the connotation of a philosophically discrete, immortal substance comprising human nature. Rather, nephesh is better interpreted as referring to a holistic life-generating principle, or the self as a living psychosomatic unity, or a “living being” (NIV Bible), or even what one might view as the whole person. One could perhaps describe humans as having “soulish properties,” but these were not instantiated in a distinct non-material soul substance (as substance dualists claimed), nor in a vitalistic animating soul principle or force that existed in addition to (and was a necessary integrated adjunct of) the physical matter of the human body (as Thomistic dualists claimed).

For example, the fact that nephesh is also used of non-human animals suggested that the term refers to living creatures more generally and not just to one part of a dualistic human. Studies of other biblical terms (e.g., ruach, basar, imago dei, pneuma, psyche, nous, soma, sarx) revealed a similar somewhat indeterminate and/or occasionally inconsistent use in Scripture, leading some scholars to question the traditional dualistic interpretation.

Additionally, under-determination with respect to the biblical data on human nature is reflected in trichotomist (or tripartite) views of human nature (body, soul, and spirit) which stand in contrast with dualistic/dichotomist views (body and soul). Trichotomists cite Genesis 2:7 as a foundational/definitive text for their view: “Then the LORD God formed man of dust from the ground [body), and breathed into his nostrils the breath of life [spirit); and man became a living being [soul)” (NASB).  Trichotomist views have been inferred from later Old Testament writings and are claimed to represent the anthropology of the Apostle Paul. Some Scriptures (and dualists) suggest the terms soul and spirit are interchangeable immaterial parts of human nature (e.g., Matt. 10:28; Luke 1:46-47; 1 Cor. 5:3; 7:34), but other passages suggest distinctions indicative of their separateness (e.g., Rom. 8:16, 1 Thess. 5:23; Heb. 4:12). In turn, dualists/dichotomists have offered a variety of responses to trichotomy, and the on-going debate has a long history.

At the very least, this ambiguous under-determination as to our nature has opened the door to alternate interpretations and (among other considerations) has contributed openness to, and advocacy of, a more monistic view. The indeterminacy leads Christian monists to argue that the relationship between body and soul (or between spirit and soul) was not clear to the ancients, nor is it clear to modern scholars; hence the possibility of alternative views.

In the monist view, the biology, psychology, and certainly the neuroscience of the archaic Hebrew, Greek, and medieval worlds was at best highly speculative and has ultimately been shown to be largely an artifact of history by modern scientific standards. Reasoning from imperfect data and understanding, the ancients attributed thought, feeling, decision-making, et al. (mind, emotion, will, etc.) to an entity they called soul (and/or spirit) and then these aspects of human nature were localized to various physical organs. For example, in most of the ancient world, the heart was viewed as the primary seat of thought and feeling (“cardiocentric view”); there are >900 biblical references to the heart, almost all can be seen as using the term metaphorically (e.g., Heb. 4:12: “thoughts and intentions of the heart”). The kidneys were often seen as the locus of reflection (e.g., Psa. 16:7; 26:2; Prov. 23:6) and the bowels as the seat of affection and “tender mercies” (Gen. 43:30; Phil. 1:8). Not until the Alexandrian, Greek, or Greek/Roman physicians (e.g., Erasistratus and Herophilus, and especially Hippocrates and Galen) did the brain begin to be appreciated as the seat of these and other soulish functions. For instance, from Galen (2^nd century AD) through the medieval period, the ventricles (fluid-filled cavities in the brain) were thought to produce and govern human nature/faculties by hydraulic mechanisms (“ventricular view”). The ventricular view was gradually replaced by the view that the brain matter itself was the seat of human nature, and modern neuroscience has increasingly corroborated this “encephalic view.”

There are various Christian monistic views which are nuanced in different ways and go by different names (e.g., non-reductive physicalism, dual-aspect monism, constitution view, etc.). A common monist argument is related to the findings of modern neuroscience: most of the faculties that Aquinas attributed to the soul – including even the most ineffable cognitive, emotional, appetitive, and other soul-related capabilities – now appear to be mediated by structures, regions, neural pathways, and functions of the brain. Brain imaging and brain manipulating tools, along with greater understanding of the neurochemical basis of behavior, have provided plausible mechanistic connections to the brain for most aspects of our behavior and many aspects of neural disease and damage (as will be briefly surveyed in the next/final installment of this article series). While we do not yet have final, detailed brain-based structure-function associations (e.g., detailed neural circuits), the massive amount of brain data that is being produced by neuroscientists (on average >200 neuroscience-related articles per day) is ever-tightening the attribution of the mind’s/soul’s properties and functions to the brain.

Since most of the soul’s previous functions are now seen as brain functions, the soul seems to many people to be an unnecessary hypothesis when it comes to accounting for human nature. We are in a situation akin to the gradual demise of vitalistic/animal spirit-based explanations which were used to account for the conundrum of biological life up until the mid-19^th century. Greater understanding of the chemistry of life, cell theory, anatomy and physiology, Mendelian/molecular genetics, molecular biology, and evolutionary theory have replaced vitalism with materialistic/monistic explanations of the nature of biological life. Neuroscience, cognitive science, sociobiology, evolutionary psychology, and related scientific disciplines are doing something similar for the understanding of our mental life and functions which were previously attributed to the soul. These sciences are providing reasonable, evidence-based materialistic/monistic/naturalistic explanations for human nature as experienced in this temporal life. Holistic dualism has morphed into dualistic holism, perhaps suggesting a nascent shift from traditional dualistic views to more monistic ones consistent with neuroscientific understandings.

In the future, since neuroscience is limited to increasing our understanding of human nature in the present life, dualism/monism debates will probably be increasingly engaged on biblical/theological turf related to the nature of our being in the afterlife. Even Scripture, however, provides only limited data regarding the nature of our existence in the afterlife, and so the dualism/monism biblical/theological debates are likely to continue for some time. Fortunately, resurrection of the body is a point of general agreement among orthodox dualist and monist Christians (affirmed by the creeds), but questions related to the afterlife persist: immediate resurrection following death? intermediate state? “soul sleep”? mechanism for maintenance of personal identity/continuity? and so on. Clearly, these are unresolved challenges for monistic views, and there are others which space prevents us from considering here.

Monist views are advanced by Christians who sincerely argue positions they claim are consistent with essential orthodox Christian doctrines. Among those arguing for Christian monistic views is an ever-increasingly diverse group of biblical and theological scholars, philosophers, neuroscientists, psychologists, and others from various scientific disciplines. Though perhaps a surprise to the average Christian in the pew, it is probably accurate to say that some sort of monistic view or other is rapidly becoming the majority view among Christian scholars.

Given the diversity of views surveyed in these two brief articles, Christian grace is called for as we continue to “reason together” about the options in light of Scripture and the best evidence we have available from other sources. A major factor in this on-going debate is the success arising from the working assumption of modern neuroscience, a concept which will be taken up in the final installment of this series.