Lesson 3: The Intellectual Ambiguities of Contemporary Culture

1) What is now called "modern" thought and culture was initiated by the skepticism and irrationalism raised by the religious wars of the Reformation and Counter-Reformation. To escape this skepticism René Descartes (1596-1650) a mathematician and, along with Galileo, a leader in modern natural science, proposed a new version of the Platonist epistemology based on innate ideas (Cartesianism) according to which certitude comes not from sense knowledge but from "clear and distinct ideas" like those of mathematics. This is the "turn to the subject" basic to all modern schools of philosophy. Its slogan is Cogito Ergo Sum (I think, therefore I am). In other words, what we are most certain of is not the external "objective" world of the senses but our own introspective knowledge of our thoughts as self-conscious and free "subjects." This approach has been basic to all modern philosophy and in Continental Europe to this day is fundamental to philosophical education as is apparent in such Vatican II theologians as Karl Rahner, a "Transcendental Thomist" and the Canadian Bernard Lonergan for whom the starting point for theology is the human subject confronted by the world ("Spirit in the World"). In its more extreme forms, as in the philosopher Husserl (1859-1938), this is epistemologically idealism. Its roots are in the Platonic tradition, but while Plato was an objective idealist (he held the Ideas to be real beings independent of his thought), Cartesianism tends to subjective idealism (all we are certain of is our own thoughts).

2) In Great Britain there was a reaction against Cartesian idealism in favor of empiricism that tended to the materialist extreme. Yet this British empiricism did not really escape Cartesianism because with John Locke (1632-1704) it taught that what we know is only our sense impressions not the material realities themselves, and thus it did not clearly distinguish between concrete sense data and abstract intellectual analysis of that data as Aristotle had done. British Empiricism generally denies the possibility of a metaphysics of both material and spiritual reality and places its trust only in a natural science confined to the material world.

3) To save natural science and the validity of human reason Immanuel Kant (1724-1804) proposed a form of idealism that held that although we cannot know the material world in itself, we can form general scientific natural laws about it as hypotheses that fit our sense experiences. These laws have universal validity in that they are based on categories innate in all human minds (these categories take the place of Plato's and Descartes' ideas). Thus truth is no longer "the conformity of the mind to things" as the ancients thought, but simply consistency in the model of reality that we mentally create. Kantianism has deeply influenced modern science that often contents itself with a hypothetical-deductive method that fits mathematical models to sense observations without claiming to describe reality itself.

4) Unfortunately this "turn to the subject" has lead in our times once again to skepticism and deconstructionism. Among British Empiricists, David Hume (1711-1776) argued for skepticism even as regards natural science, since, he claimed, the notions of cause and effect simply reflect our expectation that things will go on as usual, but they are not based on any sense data, since our senses only show us that one thing happens after another, not that one is the cause of the other. It was against this skepticism that Kant proposed his idealistic systems, but in Continental philosophy this eventually led to a variety of philosophies (life philosophy, existentialism, phenomenology, structuralism) that reduced philosophy either to a mere clarification of the language of natural science or, as with deconstructionism, holds that philosophy is just rhetoric intended to manipulate others to serve our own hidden agenda.

5) Faced with this growing skepticism and anti-rationalism, Pope Leo XIII in Aeterni Patris (1879) recommended education in the thought of St. Thomas Aquinas (1225-1274) who had introduced the Aristotelian epistemology into Catholic theology. This revival of a middle course in epistemology prepared the way for Vatican II and John Paul II's Fides et Ratio. At the same time the popes urged the assimilation to this medieval thought of modern scientific and historical advances and openness to all thought that avoids the extremes of idealism and materialistic empiricism.


1) Dulles, Craft of Theology, pp.3 52.

2) H.D. Lewis, article "Philosophy of Religion, History of" and William P. Allston, "Philosophy of Religion, Problems of" in Encylopedia of Philosophy, ed. by Paul Edwards, (New York: Macmillan, 1967). Vol. 6, pp. 276-288. The editor of this generally excellent encyclopedia has a strongly empiricist bias.


1) What is "the turn to the subject" in modern thought?

2) What are the differences and similarities between Cartesianism and Kantianism?

3) How is British Empiricism grounded in Cartesianism?

4) Why have the modern popes favored Thomism as a model for Christian philosophers and theologians?

5) Why must Thomism incorporate modern historical and scientific knowledge while preserving its middle-of-the-road epistemology?


Purchase This Course                               << Previous               Next >>                                   Return to Top