Since Plato, thinkers have recognized human mental capacities for producing images and combining them in ways that do not copy experience. Philosophers have held many theories about the origin of images. One of the most original is expressed by the seventh-century Chinese Buddhist philosopher Hsuan-tsang in his interpretation of the Yogacara writings of the Indian thinker Vasubandhu (c. fifth century C.E.). Hsuan-tsang suggested that the mind has a great storehouse consciousness of images or "seeds" that are "perfumed" into consciousness (as smells incite otherwise hidden memories) by other conscious seeds that have an emotional vector. David Hume, the eighteenth century Scottish Enlightenment philosopher, had a theory of imaginative association modeled on mechanical principles.

Synthesis and construction

Immanuel Kant, Hume's younger contemporary, revolutionized thought about imagination in the first edition of his Critique of Pure Reason (1781). He claimed that imagination is a foundational capacity for synthesis in the mind whereby stimuli or impingements from the external world are organized into the basic structures of experience such as a spatiotemporal field and the applicability of concepts to sense data, as explained in Robert Cummings Neville's Reconstruction of Thinking (1981). Romantic philosophers such as Thomas Carlyle and Ralph Waldo Emerson developed the view that the structures of imagination are more basic than the surface affirmations of conscious thought and reveal assumptions about reality that are presupposed by other forms of thought. Myths reveal truths more basic than science, for instance. The pragmatic philosopher Charles Sanders Peirce (1839–1914) gave an evolutionary interpretation of imagination such that its deep structures are more likely to be true about basic issues, because corrected over a long evolutionary development, than the reasonings of philosophers. Ray L. Hart in the twentieth century argued that imagination is central to the constitution of human beings before God and is the very form of revelation, inspiring a movement of "theologies of imagination," as analyzed by Fritz Buri in his 1985 article "American Philosophy of Religion."

Imagination has been particularly important in science. For Plato the ideal scientific imagination was mathematical, as Robert Brumbaugh has shown in his Plato's Mathematical Imagination (1954) and for Aristotle imagination was the wit to hit upon the third term connecting two otherwise unrelated topics. Whereas some people in Western philosophy might have thought that science is merely a reading off of the lessons of nature, Kant, in the Critique of Pure Reason, argued that post-Copernican science forces nature to answer questions of our own imaginative devising. Peirce, at the beginning of the twentieth century, argued at length that all hypothesis construction in science begins with an imaginative guess at the answer and then proceeds by imagination to articulate the guess in theoretical terms that might be tested. Although certain positivistic trends in mid-twentieth century philosophy of science minimized imagination in the testing of hypotheses by focusing closely on the performance of controlled experiments, a counter-movement associated with Thomas S. Kuhn (1922–1995) has been extremely influential. Kuhn argued that the controlled testing of hypotheses, or "normal science," takes place within larger assumed paradigms of what is at stake in the tests, their assumptions and their interpretations as defined by the instruments involved. "Revolutionary science" is when the paradigms themselves are criticized and changed, and this involves much imagination in stepping outside of linear inference. Imagination plays a large role in contemporary thinking about scientific creativity.

In the last two centuries scholars have used the notion of imagination to describe the set of assumptions, thought patterns, and ways of seeing or sensing peculiar to an age or culture. For instance, the imagination of the Hellenistic world of antiquity, when rabbinic Judaism and Christianity arose, included the view that the cosmos is a stack of many spatial levels of which the Earth occupies one, with perhaps many heavens above and hells below. Each level has its characteristic agents, bodies, movements, and patterns of causation. Aristotle's theory that motion above the orbit of the moon is circular whereas that below is straight-line illustrates one version of the multilevel theory; when his theory or others became unquestioned assumptions they formed part of the age's imagination. Biblical references to angels are to be understood as to beings from certain higher levels crossing the boundaries into the earthly level. God often was imagined to occupy the highest level as a being within a spatiotemporal system that includes earthly life at a different place. God's nature might be very different from that of things on the earthly level, for instance that of a pure, immaterial, infinite spirit, but it is connected with the earthly plane by the geography of the cosmic levels. In Christianity (Phil. 2) God's "Son," who has the form of God when with God in the divine heaven, descends to Earth, taking on a nature proper to the earthly level (indeed that of a slave in earthly terms). When human beings make the reverse journey to God, they must take on natures appropriate to the divine heavenly level, for instance "celestial bodies" (1 Cor. 15).

The challenge of science

The challenge of modern science to the imaginative structures of the religions formed in the ancient world is that science itself shapes contemporary imagination to make it incompatible with them. Because of modern science, people know, and assume deep in their imaginations, that beneath the Earth's surface is a molten core, not hell, and that traveling upward leads to outer space, not one or more heavens with different causal structures. Indeed the imagination shaped by modern science assumes a uniformity of measure throughout the entire cosmos: An inch is always and everywhere an inch, a chemical reaction on Earth is the same as it would be in any part of the cosmos with the same conditions, and mathematics applies equally everywhere.

So, in the modern imagination there is no "proper heavenly place" for God if God is extremely different from earthly beings. Theologians have responded to this in various ways. Process theologians (e.g. Charles Hartshorne [1897–2000]) say that God is not so different and is part of the cosmos. They explain this by saying that the differences between God and humans can be expressed within a set of metaphysical measures that apply to the finite God and ordinary things alike. Other theologians (e.g. Paul Tillich [1886–1965]) deny that God is a being at all because to be a being requires having a place; God rather is the ground or creator of all beings and places. Yet other thinkers (pantheists) say that God is identical with the cosmos and differs from any particular finite thing by being all of the things together. Many thinkers reflecting on the differences between the ancient and the modern scientific imaginations say that belief in God is simply incompatible with science, and hence are atheists. Some religious people are able to divide their imagination into one structure for religious matters and another for engaging the world in other respects, although this makes the integrating intent of religion difficult.

The study of "science and religion" sometimes attempts to reconcile contemporary scientific imagination with the ancient imagination that forms the symbols and rhetoric of traditional religions. One approach, called demythologizing and associated with Rudolf Bultmann (1884–1976), is to treat the ancient imagination as metaphorical, searching for "religious meaning" distinct from "scientific meaning." Another is to treat the modern imagination and scientific conceptions as themselves open to the literal kinds of beings and causation depicted as heavenly in the ancient imagination. So it is argued that science still allows for miracles and divine agency without denying scientific causation, as discussed in Mark Richardson and Wesley Wildman's 1996 book Religion and Science (especially case study one). The problem for religious imagination is related to but not the same as the problem of reconciling ancient and modern theories: It is a problem of apparently conflicting imaginative presuppositions that affect how people perceive and act.

Contemporary scientific imagination poses a potentially more explosive problem for modern life. Until the mid-twentieth century the modern European scientific imagination could picture atoms interacting within the void, or fields of forces affecting material objects within them. Even quantum mechanics could picture the world as having particles that travel along a path but skipping some sections relative to observation. More recent physical science has moved into a mathematical imagination that is not picturable in terms of customary space-time models. Quarks are not like tiny spinning suns, as people had earlier imagined electrons, photons, and neutrons. Only highly sophisticated mathematicians are able to comprehend the relations that added together in bulk might give rise to picturable images. Popularized expressions of many fundamental ideas in microphysics and astrophysics we know to be just plain false to the sophisticated science. This is exactly like the situation regarding certain kinds of theology whose conceptions of God are not picturable in any way and that need to be understood in purely conceptual terms, like mathematics though perhaps with a different dialectical logic. Popular religious expressions, like popular expressions of certain scientific ideas, must be said to be "just plain false," or at least highly misleading, relative to some sophisticated theology that cannot be understood except by the sophisticated. The elitism common to the mathematical imagination in science and the dialectical imagination in theology is more problematic in the religious realm. Whereas technologists can deliver the results of science to a popular world that cannot picture its theory, religions no long have technological priesthoods to mediate unpicturable truths easily to people whose credulity requires traditional religious language.

See also KANT, IMMANUEL

ROBERT CUMMINGS NEVILLE