Influx

Philological Background and Basic Sense

Influx derives from the Latin influxus, meaning a “flowing in” or “stream,” from in- (“into”) and fluere (“to flow”). In everyday English, influx denotes an incoming flow of people, things, or influences (for example, an influx of migrants or capital). In philosophical and theological usage, however, the term acquires a more technical meaning, referring to the way in which one being, cause, or realm exerts influence or causal efficacy upon another.

In scholastic Latin, phrases such as influxus physicus (“physical influx”) or influxus divinus (“divine influx”) were used to describe both ordinary causal relations in nature and the special mode of action by which God, spirits, or intelligences were thought to “flow into” and act upon created beings. The notion of “influx” thus stands at the intersection of metaphysics, theology, and later philosophy of mind.

Scholastic and Early Modern Debates on Causal Influx

In medieval and early modern scholasticism, influx was closely tied to the theory of efficient causation. To say that a cause has an influx into an effect is to say that something—be it form, actuality, or motion—is communicated or “flows” from cause to effect.

Thomas Aquinas and many scholastic authors describe God’s relation to the world as a kind of continuous influx of being: created substances are dependent at every moment on the divine act, which “flows into” them as their conserving cause. At the created level, scholars debated the nature of influxus physicus, the “physical” or natural influx by which substances act on one another, transmitting motion, qualities, or forms.

With the rise of Cartesian dualism, the notion of influx became central to the problem of mind–body interaction. If mind (res cogitans) and body (res extensa) are distinct substances, how can they exercise influx on each other—how can a mental decision move an arm, or bodily injury cause a pain? Descartes posits interaction but does not fully explain the mechanism of influx, prompting alternative theories:

• Occasionalism (notably in Malebranche) denies any genuine created influx between finite substances. On this view, what appear as causal interactions are merely “occasions” for God’s action. A bodily event does not truly flow into a mental event; instead, God directly produces the mental state on the occasion of the physical one.
• Other thinkers defend some form of real influx, insisting that created substances genuinely act on one another, even if the precise metaphysical mode of this influx remains obscure.

Immanuel Kant later criticizes the idea of influxus physicus when it is understood as a mysterious transfer of something between intrinsically self-subsistent substances. For Kant, we know substances only through their lawful relations; speaking of an additional “influx” beyond these relations is, in his view, speculative and unjustified. In this way, philosophical usage moves from a relatively concrete image of “flowing in” toward a more abstract critique of the very idea of hidden metaphysical transfers.

Spiritual and Idealist Notions of Influx

The term influx also acquires a pronounced spiritual and psychological sense in early modern theology and later idealist thought.

In Christian theology, especially in mystical and pietistic traditions, divine grace or the Holy Spirit is sometimes described as an influx into the soul: a non-coercive but real inflow of life, light, or love that elevates and transforms human faculties. Scholastic distinctions between natural and supernatural influx helped shape debates over grace, free will, and divine concurrence.

A particularly systematic use appears in Emanuel Swedenborg. For Swedenborg, influx is a central technical concept describing how higher spiritual realities “flow into” lower ones through correspondences. God’s life, he argues, flows into spiritual worlds, then into the human mind, and finally into the natural world, producing a layered order of effects. Human thoughts and affections are thus shaped by constant spiritual influx, though individuals remain responsible for how they receive and appropriate it. In this framework, influx is not merely causal transfer but an ongoing structural relation between levels of reality.

In various forms of German idealism and Romanticism, similar imagery appears, though often without the specific term. The influx of the Absolute into finite spirit, or of nature into consciousness, evokes dynamic relations where the finite is permeated by a deeper ground. When the word itself is used, it typically serves to articulate how universal spirit, reason, or life manifests within individual minds and historical processes.

Contemporary and Broader Usage

In contemporary analytic philosophy, influx is rarely employed as a technical term. It mainly appears in historical discussions—of scholastic metaphysics, early modern occasionalism, or Swedenborgian psychology—where scholars reconstruct older debates about causal influx, divine action, and mind–body interaction. In such contexts, “influx” serves as a marker of specific historical theories rather than a live metaphysical posit.

Outside specialist philosophy, influx survives in two main ways:

1. As a general metaphor for any significant incoming flow—of information, people, influences, or resources.
2. In some theological, mystical, and esoteric circles, where it retains the sense of spiritual or divine inflow shaping human consciousness or history.

Across these usages, the underlying image remains consistent: influx points to a relation where something “flows into” something else—whether as physical cause, mental influence, spiritual grace, or social force. Philosophical reflection has alternately sought to explain, formalize, or dissolve this image, making “influx” a useful lens on changing conceptions of causation, interaction, and dependence in the history of ideas.