Interview with Dr. Geisler regarding Thomas Aquinas

Thomas Aquinas: Christian History Interview – He’s Our Man
Evangelicals can embrace a rich inheritance from Aquinas.
by Norman L. Geisler
In a 1974 Christianity Today article marking the 700th anniversary of Aquinas’s death, author Ronald Nash said some nice things about the deceased but ultimately judged his system of thought “unsuitable for a biblically centered Christian philosophy” and “beyond any hope of salvage.” Norman Geisler disagreed with that assessment then, and he disagrees with it now. We asked Dr. Geisler, president of Southern Evangelical Seminary and author of Thomas Aquinas: An Evangelical Appraisal (Baker, 1991), for his evaluation of the Angelic Doctor. . .
For additional resources by Dr. Geisler on Roman Catholicism, please visit

Brief Comments on Logic

Here is a short clip of Dr. Geisler teaching on the graduate level about and defending the Laws of Logic.


The full course on Logic should be available for purchase at soon.

Also consider Dr. Geisler’s book/e-book titled Come, Let us Reason: An Introduction to Logical Thinking from here


A Response to Philosophical Postmodernism

A Response to Philosophical Postmodernism

by Norman L. Geisler


A Brief Background of Postmodernism

Premodernism is often thought of as the time before 1650 A.D.  The dominant theme was metaphysics or the study of being (reality). Modernism then began with Rene Descartes around 1650 and turned attention to epistemology or how we know.  The precise date of Post-modernism is in dispute.  Although its roots go to Friedrich Nietzsche (d. 1900), it did not begin to take shape until around 1950 with Martin Heidegger and began to occupy a front seat in the discussion a decade or two later with Derrida.  The primary focus of Post-modernism is hermeneutics or how to interpret.  The object of interpretation can be history, art, or literature, but deconstructing it is the center of focus.

Someone has illustrated the difference between the three periods of thought by the image of a referee.  The Pre-modern referee says: “I call them like they are.”  The Modern referee claims, “I call them like I see them.”  But the Post-modern referee declares: “They are nothing until I call them.”

Forerunners of Postmodernism

Modern western thought begins with two main streams: empiricism and rationalism.  David Hume represented the former and Rene Descartes the latter.  The empiricists stressed the senses and the rationalist the mind.  The empiricists began a posteriori in sense experience, but the rationalist began a priori with innate ideas in the mind.  Immanuel Kant synthesized the two streams, arguing that the senses provide the content of our knowledge but the mind gives form to it. He claimed that the mind without the senses is empty, but the senses without the mind are blind.  The unfortunate result of his brilliant but tragic synthesis was agnosticism. We cannot know reality as it is in itself but only as it is after it is mediated to us through the senses and formed by the categories in our mind.  Hence, metaphysics—knowing reality in itself—is impossible.


Kantian agnosticism gave rise to ren Kierkegaard’s fideism on the one hand and Nietzsche’s atheism on the other hand. Acknowledging the Kantian gulf between appearance and reality, Kierkegaard suggest a “leap of faith” to the “wholly other” God who transcends all capacity to know him with our minds.  Nietzsche, on the other hand preferred not to leap to an unknown God but to pronounce God dead and simply go on willing the eternal recurrence of the same state of affairs forever.


In the absence of any absolute Mind to express any absolute meaning, Ludwig Wittgenstein built on Frege’s conventionalism and insisted that we are all locked inside a linguistic bubble which allows us to make no cognitively meaningful statements about the mystical (metaphysical) beyond.  That is to say, without saying God is dead, he insisted that all meaningful talk about God is “dead” (i.e., meaningless).


Borrowing Edmund Husserl’s phenomenological method, the later Martin Heidegger posited a new hermeneutic which, giving up on any metaphysical knowledge of reality, attempted to retrieve rays of truth to shine through poetry (particularly that of Friedrich Holderlin). It is out of this context that Jacque Derrida conceived his hermeneutical method of deconstructions by which one deconstructs a text and reconstructs it over and over again.  Before we analyze that more carefully, it will be helpful to contrast Modern and Post-Modern thought in general.

Contrast of Modernism and Post-Modernism


As can be seen from the following chart, there is an import shift between modern and post-modern thought.  The general shift is from epistemology to hermeneutics; from absolute truth to relative truth; from seeking the author’s meaning finding to the reader’s meanings; from the structure of the text to destructing the text; from the goal of knowing truth to the journey of knowing:


Modernism                              Postmodernism

Unity of thought                      Diversity of thought

Rational                                   Social and psychological

Conceptual                              Visual and poetical

Truth is absolute                     Truth is relative

Exclusivism                             Pluralism

Foundationalism                     Anti-foundationalism

Epistemology                          Hermeneutics

Certainty                                 Uncertainty

Author’s meaning                   Reader’s meanings

Structure of the text                Deconstructing the text

The goal of knowing               The journey of knowing

                                  The Nature of Postmodernism

Postmodernism is a condition where [since God is dead] “anything is possible and nothing is certain” (Vaclav Havel).  Nietzsche pronounced “God is dead,” but there are several different meanings that can be given to this phrase “God is Dead.”  It can mean God is dead–

  1. Epistemologically–Kant
  2. Mythologically—Nietzsche
  3. Dialectically—Hegel
  4. Linguistically—Ayer
  5. Phenomenalogically—Husserl
  6. Existentially–Sartre
  7. Cognitively—Wittgenstein
  8. Hermeneutically—Heidegger/Derrida

Of course, many of these thinkers also believe God is dead actually(e.g., Nietzsche, Sartre, and Derrida), but this is beside the point at hand here, namely, the methodology of Post-Modern deconstructionism.

Jacques Derrida: Post-Modernism

Two of the dominant figures in Post-modernism are Jacque Derrida and Paul-Michel Foucault.  Derrida wrote:  Of Grammatology (‘67); Speech and Phenomena (‘67); Writing and Difference (‘67); Limited Inc. (1970); Post Card: From Socrates, Freud and Beyond (1972); Specters of Marx (1994).

        Foucault wrote: Madness and Civilization (1961); Death and Labyrinth (1963); The Order of Things (1966); Discipline and Punish (1975);Archaeology of Knowledge (1976), and History of Sexuality (1976-1984).
The starting point for their post-modern thought was Nietzsche’s death of God.  For if

If there is no Absolute Mind, then there is-

  1. No absolute truth (epistemological relativism)
  2. No absolute meaning (semantical relativism)
  3. No absolute history (reconstructionism)

And if there is no Absolute Author, then there is—

  1. No absolute writing (textual relativism)
  2. No absolute interpretation (hermeneutical relativism)

And if there is no Absolute Thinker, then there is—

  1. No absolute thought (philosophical relativism)
  2. No absolute laws of thought (anti-foundationalism)

And if there is no Absolute Purposer, then there is—

  1. No absolute purpose (teleological relativism)

If there is no Absolute Good, then there is—

  1. No absolute right or wrong (moral relativism)

The Death of All Absolute Values in Post-Modernism

“Without God and the future life?  How will man be after that? It means everything is permitted now” (The Brothers Karamazov, Vintage, 1991, p. 589).  As Jean Paul Sartre put it, “I knew myself alone, utterly alone in the midst of this well-meaning little universe of yours.  I was like a man who’s lost his shadow.  And there was nothing left in heaven, no right or wrong, nor anyone to give me orders” (Sartre, The Flies, 121-122 in No Exit and Three Other Plays).  Aldous Huxley acknowledge this same conclusion when he wrote, “The liberation we desired was simultaneously liberation from a certain political and economic system and liberation from a certain system of morality.  We objected to the morality because it interfered with our sexual freedom” (Ends and Means, 272).

Perhaps no one described it better than Bertrand Russell when he wrote of a world without God:  “Man is the product of causes which had no prevision of the end they were achieving…. His origin, his growth, his hopes and fears, his loves and his beliefs, are but the outcome of accidental collocations of atoms…. All the noonday brightness of human genius, are destined to extinction in the vast death of the solar system…. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul’s habitation henceforth be safely built” (Bertrand Russell, “A Free Man’s Worship” (in The Basic Writings of Bertrand Russell, 67).

In short, the root of Post-modernism is atheism and the fruit of it is relativism—relativism in every area of life and thought.  Of particular interest is the post-modern attack on foundationalism, history, and textual interpretation and how this has affected Christian thought.

The Attack on Foundationalism

Foundationalism is the view that there are fundamental self-evident first principles which form the basis of all knowledge. It is at least as old as Plato and Aristotle in the Western world, though it has been the unwitting foundation of Christian Thought from the beginning of time.

There is an important distinction between two basic kinds of foundationalism often neglected by post-modern thought.  There is deductive foundationalism and reductive foundationalism.

Deductive foundationalism springs from modern rationalist like Benedict Spinoza and Rene Descartes.  It is based on a Euclidian geometric model whereby certain axioms are defined as self-evident and all other truth is deduced from them.  The problem with this is that not all axioms are necessary.  Different axioms are possible, both in mathematics and philosophy. Further, these rational axioms are empty.  They yield no knowledge about reality.  For example, saying “All triangles have three sides” does not tell us there are any triangles.  It merely says that if there are any triangles, then by definition they must have three sides.

Reductive foundationalism finds roots in Aristotle and was embraced by the great Christian thinker Thomas Aquinas.  It states that all truths are reducible to (or based on) self-evident first principles. Every statement not evident in itself must be evident in terms of something else. But there cannot be an infinite regress of non-evident statements. For an endless regress of explanations is nothing more than an attempt to explain away the need for an explanation.  Hence, there must be first self-evident statements in terms of which non-evident statements are known to be true.

First principles of knowledge are self-evident.  That is, they are a statement where the predicate term is reducible to the subject term, though not always deducible from it. The basic laws of thought include the following:

Several things are noteworthy about these first principles of thought.

First, they are all first principles of thought and being.  Why?  Because “If there were an infinite regress in demonstration, demonstration would be impossible, because the conclusion of any demonstration is made certain by reducing it to the first principle of demonstration” (Aquinas, Commentary on the Metaphysics of Aristotle, 244).  Or, as C. S. Lewis aptly put it, “You cannot go on ‘explaining away’ forever: you will find that you have explained explanation itself away.  You cannot go on ‘seeing through’ things forever. The whole point of seeing through something is to see something through it.  It is good that the window should be transparent, because the street or garden beyond it is opaque.  How if you saw through the garden too?  It is no use trying to see through first principles.  If you see through everything, then everything is transparent.  But a wholly transparent world is an invisible world.  To ‘see through’ all things is the same as not to see” (The Abolition of Man, 91).

Second, they self-evident in the reductive sense. That is, there predicate is reducible to their subject.  So that once one understand the meaning of the subject and predicate he can immediately see that they are self-evident.  For example, once one knows what the words “bachelor” and “unmarried” mean, then he knows immediately that “all bachelors are unmarried men.”  Likewise, once one knows this is a three-sided figure, then he sees immediately that it is a triangle.

Third, they are also undeniable.  That is, every attempt to deny them, affirms them (at least implicitly) in that attempted denial.  Take, for example, the Law of Existence.  I cannot deny that something exist without existing to make the denial.  The claim that I do not exists, implies that I do exist to make the denial.

Fourth, these first principles apply to all of reality.  They are metaphysical first principles.  Unlike deductive foundationalism, they are not empty and vacuous.  They are first principles of being (reality). They begin with something exists.

Fifth, from these principles one can demonstrate the existence and central attributes of God. For if something exists (#1), and if nothing cannot cause something (#5), then something eternal and necessary must exists. And whatever else exists, then it must be similar to God in its being (#7).  But not all being is a necessary being (#6). For example, I am a contingent being, that is, I am, but I might not be.  My non-existence is possible.  But I am a knowing and moral being (which is undeniable).  Hence there must be an eternal and necessary Being who is a knowing and moral Being that exists (i.e., God).  And if God exists, then absolute thought, values, and meaning also exists.  In short, post-modernism is wrong.


A Critique of Postmodernism


            This critique can be applied to other areas of post-modern thought, for example, to deconstructionism in history and textual interpretation.  Let’s briefly apply it to history.


A Critique of Post-Modern View of History


According to a post-modern view of history, we must deconstruct all historical accounts of the past since they are relative and not objective.  This, of course, would be destructive of  orthodox Christianity since it is a historic religion.  We believe, as the Apostles’ Creed says, that Jesus “was born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died, and was buried… [and] the third day He arose again from the dead.”  These are all historical claims, and if history is unknowable, then we cannot know these to be true.  But is history really unknowable?  Let’s briefly examine the post-modern arguments for the unknowability of history. One historical relativist said, “The event itself, the facts, do not say anything, do not impose any meaning. It is the historian who speaks, who imposes a meaning” (Carl L. Becker, “What Are Historical Facts?” in The Philosophy of History in Our Time, p. 131).

However, there is a serious self-defeating problem with this claim.  How can one know that something is not objective history unless he has an objective knowledge of history that enables him to say that a particular view of history is not objective.  One cannot know not-that unless he knows that.  And he cannot know not-objective history unless he knows objective history.  Second, it is self-defeating to deny objectivity in history.  Even Charles Beard, the apostle of historical relativity himself, wrote: “Contemporary criticism shows that the apostle of relativity is destined to be destroyed by the child of his own brain.”  For, “If all historical conceptions are merely relative to passing events…then the conceptions of relativity is itself relative.”  In short, “the apostle of relativity will surely be executed by his own logic” (Meyerhoff ed., The Philosophy of History in Our Time, 138, emphasis added).

 A Critique of a Post-modern Views of Hermeneutics

There are several characteristics of a deconstructionists view of interpretation.

First, it is based in conventionalism.  This is  the view that all meaning is culturally relative.  However, this too is self-defeating for if “all meaning is culturally relative” then even this statement would be culturally relative.  Yet it claims to be a statement about cultural relativity not one of cultural relativity.

Second, post-modern hermeneutic claims that there is no objective meaning.  For all statements are made from a subjective perspective.  However, this too is self-destructive for it amount to saying that it is an objective statement about meaning that no statements are objectively meaningful.

Third, it denies that there is a correspondence between our statements and their object. This denies the correspondence view of truth.  But the problem with denying that truth corresponds to reality is that this very denial claims to correspond to reality.  So, one cannot deny statements correspond to reality without making a statement he believes corresponds to reality.

Fourth, post-modern hermeneutics is a form of linguistic solipsism.  Following Wittgenstein, Derrida believes that we are locked inside of language in a kind of linguistic bubble and cannot get out.  However, this is a form of the “nothing-buttery” fallacy.  For all statements that imply we can know nothing but what is inside the linguistic bubble imply that we have knowledge ofmore than what is inside the bubble.  Like the Kantian contradiction, one cannot know about reality that he cannot know anything about reality.  Language is not a wall that bars us from reality; it is a window that expresses the reality we know.

This linguistic solipsism fallacy is based on the failure to recognize that creation is analogous to the Creator.  There must be a similarity between the Cause of finite being and the Infinite Being that caused it.  For one cannot give what he does not have to give.  He cannot produce what he does not produce.  Thus, the Source of all being must be similar to the being that he brings into being.[1]

Fifth, according to post-modernism, logic is language dependent.  The laws of thought are, therefore, culturally dependent.  But this is clearly contrary to fact—the fact that language is based on logic, not the reverse.  For the basic laws of thought (enumerated above) operate in ever language and culture, as do the basic laws of mathematics.  Logic transcends culture and makes cross-cultural communication possible.  The very claim that the Law of Non-contradiction is not applicable to all cultures is itself a non-contradictory statement about all cultures.

Sixth, another post-modern hermeneutical premise is that meaning is determined by the reader, not by the author.  For they claim that every text is understood in a context and every reader brings a new context to the text.  Hence, it is not the meaning of the author that is the true meaning of a text by the meanings of the readers.  However, here again we are faced with a self-stultifying claim.  For no post-modernist desires us to give our meaning(s) to his words. He expects us to take the meaning of his words (i.e., the author’s meaning).  So, the denial that the author’s meaning is the correct meaning implies that the authors’ meaning is the correct meaning.

The Problems with Post-modernism

In summation, the problems with post-modernism are: (1) It can’t be thought consistently; (2) It can’t be spoken consistently, and (3) It cannot be lived consistency.  Why? Because it is based on atheism, and atheism cannot be thought, spoken, or lived consistently.  Evidence for the inability to live atheism consistently comes from the lives of atheists themselves. 

Evidence for atheists that atheism cannot be lived consistently

Atheist Jean Paul Sartre wrote, “I reached out for religion, I longed for it, it was the remedy. Had it been denied me, I would have invented it myself… I needed a Creator….” (The Words, 102).   Atheist Albert Camus added,   “For anyone who is alone, without God and without a master, the weight of days is dreadful” (The Fall, 133).  Even Nietzsche wrote a poem to an “Unknown God,” crying out:  “Unknown one! Speak. What wilt thou, unknown-god?… Do come back With all thy tortures! To the last of all that are lonely, Oh, come back!… And my heart’s final flame –Flares up for thee! Oh, come back, My unknown god! My pain! My last–happiness!” (Thus Spoke Zarathustra, Part Four, “The Magician”).

Bertrand Russell expressed a revealing moment when he wrote to a lady friend, “Even when one feels nearest to other people, something in one seems obstinately to belong to God…–at least that is how I should express it if I thought there was a God.  It is odd, isn’t it? I care passionately for this world and many things and people in it, and yet…what is it all?” There must be something more important one feels, though I don’t believe there is” (emphasis is his).

A number of years, before the iron curtain was lifted, while I was returning from Europe, I was given Time magazine.  The cover caught my attention.  It read: “God is Dead; Marx is dead, and I am not feeling too well either” (Timecover, European edition, 1978). Nietzsche wrote, “I hold up before myself the images of Dante and Spinoza, who were better at accepting the lot of solitude. Of course, their way of thinking, compared to mine, was one which made solitude bearable; and in the end, for all those who somehow still had a “God” for company…. My life now consists in the wish that it might be otherwise…and that somebody might make my “truths” appear incredible to me…” (Letter to Overbeck, 7/2/1865).

Even David Hume could not live his skepticism.  He wrote:  “Most fortunately it happens, that since reason is incapable of dispelling these clouds [of doubt], nature herself suffices to that purpose, and cures me of the philosophical melancholy and delirium…” (A Treatise on Human Nature1.4.7).  So, what did he do?  He said, “I dine, I play a game of backgammon, I converse…; and when after three or four hours’ amusement, I would return to these speculations, they appear so cold, and strained, and ridiculous, that I cannot find in my heart to enter into them any farther” (ibid. 1.4.7).

Famous unbelieving historian and philosopher Will Durant wrote: “I survive morally because I retain the moral code that was taught me along with the religion, while I discarded the religion….  You and I are living on a shadow…. But what will happen to our children…? They are living on the shadow of a shadow” (Chicago Sun-Times 8/24/75 1B).

The British Humanist Magazine charged that Humanism is almost “clinically detached from life.”  It recommends they develop a humanist Bible, a humanist hymnal, Ten Commandments for humanists, and even confessional practices!  In addition, “the use of hypnotic techniques–music and other psychological devices–during humanist services would give the audience that deep spiritual experience and they would emerge refreshed and inspired   with their humanist faith…” (1964). I have composed some hymns for them: “Socrates, Lover of My Soul,” “No One Ever Care for Me like Plato,” and “My hope is built on nothing less than Jean Paul Sartre and nothingness”! A hymn for a Post-modernists might read like this:

                           “Open my eyes that I may see,

                   More of my own subjectivity.

                           Help me, Derrida, ever to be

                  All absorbed in uncertainty.

                           Then I’ll know what it is to be

                        Lost forever in postmodernity.”

In summary, when atheists themselves evaluate atheism they conclude it like living on s a “shadow of a shadow.”  It is not “bearable.”  It is “dreadful,”even “cruel.” It even leads to “delirium.” The main point is that postmodernism is not only unthinkable and unspeakable, but it is unlivable.

Atheist Albert Camus declared that “Nothing can discourage the appetite for divinity in the heart of man” (Camus, The Rebel, 147).  Blaise Pascal insisted that there is a God-sized vacuum in the human heart which nothing but God can fill.  He wrote: “What else does this craving, and this helplessness, proclaim but that there was once in man a true happiness, of which all that now remains is the empty print and trace? This he tries in vain to fill with everything around him… though none can help, since this infinite abyss can be filled only with an infinite and immutable object; in other words by God himself” (Pascal, Pensees # 425). Former Atheist Francis Collins who headed up the human genome project asked:  “Why would such a universal and uniquely human hunger [for God] exist, if it were not connected to some opportunity for fulfillment?… Creatures are not born with desires unless satisfaction for those desires exists.  A baby feels hunger: well, there is such a thing as food.  A duckling wants to swim: well there is such a thing as water” (The Language of God, 38).  So, if there is a God-sized vacuum in the human heart, then nothing smaller than God will be able to fill it.

Atheist Sigmund Freud claimed that “What is characteristic of illusions is that they are derived from human wishes.”  As for “religious doctrines,” “all of them are illusions and insusceptible of proof” (The Future of an Illusion, 49-50). However, as it turns out it is the atheist who has the illusion.  For Freud never made a study of believers on which he based his view.  On the contrary, recent studies show that belief in God leads to a better and happier life. Former Freudian did a study of great atheist and found that they were fatherless wither actually of functionally and that, rather than believers creating the Father (God), atheists are attempting to kill the Father (Paul Vitz, Faith of the Fatherless). He wrote, “Indeed, there is a coherent psychological origin to intense atheism” (p. 3). “Therefore, in the Freudian framework, atheism is an illusion caused by the Oedipal desire to kill the father (God) and replace him with oneself” (p. 13).

Indeed, in Nietzsche’s famous quote about “God is dead” the next line is “and we have killed him.”  French existential atheist Jean Paul Sartre, illustrates the point in his own autobiography when he wrote: “I had all the more difficulty of getting rid of him in that he had installed himself at the back of my head.… I collared the Holy Ghost in the cellar and threw him out; atheism is a cruel and long-range affair; I think I’ve carried it through. I lost my illusion” (The Words, 252-253).

However, even though Sartre had given up on God, God had not given up on him.  Before Sartre’s death he is recorded as saying, “I do not feel that I am the product of chance, a speck  of dust in the universe, but someone who was expected, prepared, prefigured.  In short, a being whom only a Creator could put here” (National Review, 11 June, 1982, p. 677).  Indeed, Sartre was disowned by his own mistress as a “turncoat” and visited by a Christian minister regularly before his death.  I have in my file a letter from missionaries in France who knew Sartre who had expressed to them his regret on how many young people he had led astray with his atheistic thought.



[1] Of course, there must be a difference between Creator and creature since He is an infinite kind of Being and we are finite beings.  He is a Being with no potentiality for non-being, and we are contingent beings which have the possibility not to be.  God is Pure Actuality (with no potential not to exist), and all creatures are actualities with the potentiality not to exist.

Copyright © 2012 Norman L. Geisler – All rights reserved

Further resources:

A History of Western Philosophy Vol. 1

A History of Western Philosophy Vol. 2