Popper’s via negativa

Negative theology (also known as apophatic theology) is an approach to the study of the divine nature that emphasizes that our knowledge of God is (either largely or wholly, depending on how far one wants to take this) knowledge of what God is not, rather than what God is.  There is an interesting parallelism between this idea and Karl Popper’s account of the nature of scientific knowledge.  I don’t claim that this necessarily has much if any significance for either theology or the philosophy of science (and I’m no Popperian in any event), only that the parallels seem real.  Make of them what you will.

Note first that negative theology is not a kind of atheism, nor even agnosticism as that is usually understood.  The negative theologian does not deny that God exists, nor even, necessarily, that we can know that God exists.  The claim is rather that God’s essence or nature (as opposed to his existence) is opaque to us, so that a sound theology must characterize it mostly or entirely in negative terms.

Maimonides is a famous advocate of this approach.  Another is Aquinas, though the apophatic element of his theology, important as it is, is sometimes overstated.  As Aquinas says in De Potentia:

Moreover the idea of negation is always based on an affirmation: as evinced by the fact that every negative proposition is proved by an affirmative: wherefore unless the human mind knew something positively about God, it would be unable to deny anything about him.  And it would know nothing if nothing that it affirmed about God were positively verified about him. (Question VII, Article 5)

All the same, Aquinas emphasizes that because of the dependence of human cognition on the senses, our positive knowledge cannot extend as far as the divine essence.  We can say that God is not caused, not changing, not in time, not material, and so on, but lack the capacity for much in the way of a positive characterization.

Now, Popper famously presents his falsificationist philosophy of science as a response to Hume’s problem of induction.  The Humean, on the basis of his empiricist premises, denies that we can be rationally justified in inferring universal laws from observation of particular cases.  Popper agrees with this, but says that it doesn’t matter because science is not really concerned with justifying anything in the first place, but rather with falsifying claims.  We can know what has been proved false, but can never prove any scientific claim true.  Corroborated scientific theories are those which have not yet been proven false, but at some point they too are bound to be falsified and replaced by other (only tentatively accepted) theories which will themselves eventually be falsified. 

Popper’s confinement of certain scientific knowledge to negative claims about the natural world is analogous to the apophatic theologian’s confinement of theological knowledge to negative claims about the divine nature.  It has a similar source in the idea that knowledge must be grounded in experience (where the Humean has a much thinner conception of “experience” than an Aristotle or Aquinas, which is why Humeans are bound to think we can know much less about even the natural world than Aristotle or Aquinas did).  Popper also rejects essentialism, so that he thinks we cannot know the essences of natural phenomena (in a way that is analogous to how Aquinas, though an essentialist, thinks we cannot strictly know the divine essence). 

Yet Popper is a realist and an objectivist.  He does not deny the reality of the natural world or that our cognitive faculties are capable of making objectively true judgments about it.  It’s just that our knowledge of it is largely negative.  This is analogous to how the apophatic theologian does not deny that God exists or that we can know that he does, but only that we can have much in the way of positive knowledge of his nature.

Is there some reason for these parallels between Popper’s philosophy of science and negative theology?  Or are they merely coincidental?  I’m inclined to say that they are not entirely coincidental, though not because either had any direct effect on the other.  Rather, as I have indicated, their similarities are perhaps a result of a common foundation in empiricism (or at least, such a foundation is to be found in the Aristotelian style of negative theology one sees in a thinker like Aquinas).  Though, an important difference between the views also has the same foundation.

What I mean is this.  Aquinas’s negative theology is grounded in his Aristotelian brand of empiricism.  Because the empirical world is the natural subject matter of human cognition, we can’t form much in the way of a positive conception of what lies beyond it.  All the same, the Aristotelian brand of empiricism has a much more ambitious conception of what the senses can reveal about the natural world than modern, post-Lockean empiricism does.  It allows, for example, that the intellect can abstract the essences of physical things of a certain kind from observations of particular instances of that kind.  This makes possible a more robust positive knowledge of the natural world than is possible on Popper’s account.

Popper himself was certainly critical of certain aspects of modern empiricism, but he nevertheless worked within its broad, very modest conception (and, from the Aristotelian point of view, excessively modest conception) of what experience could reveal about nature.   Hence, where the Aristotelian negative theologian would say that we can have little or no positive knowledge of the divine essence but can have such knowledge about the natural world, Popper denies we can have it even about the natural world.  In both cases the view is (or at least sometimes is, in the case of negative theology) grounded in a view about the limits of empirically grounded knowledge, but in Popper’s case the limits are more severe.

Related posts:

Tugwell on St. Albert on negative theology

McCabe on the divine nature

Dharmakīrti and Maimonides on divine action

Lao Tzu’s negative theology

A note on falsification

Popper’s World 3

Jackson on Popper on materialism