Whether this claim is valid or not very much depends on the concept of God in question.  If God is inside time, everlasting but personal – as the God of Abraham and Isaac in the Bible seems to be – then using religious language in a positive and univocal way seems reasonable.  On the other hand, if God is eternal outside time – as the God of the Philosophers, the Prime Mover, “that than which nothing greater can be conceived of” seems to be – then using words coined to describe things within time seems more problematic.  Maimonides, the most famous proponent of the Via Negativa, was heavily influenced by the Philosophy of Plato and Aristotle and so saw God as eternal outside time.  Given this, his claim in the “Guide for the Perplexed” that… “To give a full explanation of the mystic passages of the Bible is contrary to the law and to reason… God cannot be compared to anything…” and his proposal that the most that can be said about God is what God is not i.e. God is not limited, evil, something physical etc… seems persuasive.  Nevertheless, Maimonides’ Via Negativa, his apophatic way of approaching God leaves religion in a difficult position.  Religions make positive claims about God; the Holy Books and doctrines of all religions are full of them!  Maimonides’ approach makes religion die the death of a thousand qualifications.  Believers need to have something positive to fix their faith on, not silence, the empty space left by negations and a lot of small print saying that Holy Texts can’t be understood to mean what they say.  The Via Negativa – for all its logical appeal and for all its possibilities in terms of framing that language of spirituality and personal faith – is far from being the best approach to religious language. 

In a sense, Christianity is defined by the Nicene Creed:

“We believe in one God,
the Father, the Almighty,
maker of heaven and earth,
of all that is, seen and unseen. 

We believe in one Lord, Jesus Christ,
the only Son of God…”

Approaching the Creed from the Via Negativa is problematic.  Admittedly, it doesn’t start too badly.  One God.  Oneness is a quality being positively ascribed to God.  Is oneness a concept bound by time and space?  Arguably.  Maimonides might replace this line with “We believe in a God who is not many…” but the sense is very much the same.  Nevertheless, things quickly go downhill.  We believe in God “the Father”… clearly “Father” is a word rooted in time and space.  Maimonides – along with Christian proponents of the Via Negativa such as Tertullian, St Cyril of Jerusalem and Pseudo-Dionysus – might have to admit that the word has no positive meaning when applied to God and worse, that it is likely to be positively misleading about His nature.  While St Cyril’s point that believers should “candidly confess that we have not exact knowledge concerning Him…” (Catechetical Homilies), this approach is unlikely to have found favour at the Council of Nicaea or in Churches today.  The central Christian mission would be a lot more difficult if believers openly confessed that they have little idea what it is they believe in!  As Maimonides wrote “However great the exertion of our mind may be to comprehend the Divine Being or any of the ideals, we find a screen and partition between God and us.” (Guide for the Perplexed)  This doesn’t offer people much incentive to be baptized, attend Church or read the Gospel; it pushes people towards deism or non-denominational “spirituality”.  In this way, the Via Negativa is not the best approach to religious language as it makes religion dysfunctional.  

Further, there is a better alternative to the Via Negativa in the form of Aquinas’ doctrine of Analogy.  Aquinas read Maimonides and was persuaded both by his concept of God and by his skepticism concerning the positive meaning of terms applied to God.  He strongly disagreed with the univocalism employed by scholars like St Anselm and absolutely rejected the idea that people can know and describe the nature of God sufficiently to analyze it and find necessary existence within it a priori, as proponents of the ontological arguments do.  In Summa Theologica 1:2:2 Aquinas wrote “because we do not know the essence of God, the proposition “God exists” is not self-evident to us; but needs to be demonstrated by things that are known to us…”  In Summa Theologica 1:2:3 he responded to the question “Is God a body” by making quite clear that the meaning of words applied to God can only be understood in a strictly limited and analogical sense.   Aquinas argues that words applied to God have meaning as analogies of being (1) and sometimes discusses two separate senses in which meaning should be understood; analogies of attribution (2) and analogies of proportion (3).

1. Most importantly, God’s being is not the same as our being – he is Wholly Simple and timeless and as such has no potential.  The meaning of words applied to God have to be consistent with the mysterious, timeless nature that we know that he must have as a result of reasoning from movement, causation and contingency.  For Aquinas, when believers say that God is good they cannot understand that God is morally good, because that implies freedom and choice which are concepts which only make sense in time.  God is timeless and eternal, so His goodness can only be timeless and eternal – goodness in the sense of perfection and the fulfilment of nature only.  Hence, there is a positive sense in which attributes positively ascribed to God can have meaning; that in which they are compatible with His being or nature.
2. In addition, the meaning of terms applied to God and to earthly things has an overlap in the way that I might say that I am healthy and my yoghurt is healthy.  Healthy is a property primarily of living creatures like me and only secondarily of foods or activities which contribute to my health.  According to John Milbank, Aquinas suggests that the primary sense of attributes such as “good” relate to God and the meaning of the word in an earthly sense is only secondary.  There IS a positive connection between the meaning of attributes applied to God and earthly things; the connection is not large but it is rationally defined.
3. In addition, God’s unchangingly perfect and actual nature dictates that he must be 100% everything that can be ascribed to Him.  God cannot fall short, because to do so implies potential which is not compatible with God’s timeless nature.  Given this, God is the scale against which we make judgements about things in this world.  If I say “Jamie Vardy is a great footballer” I have to have an idea of what greatness means.  Vardy can only fulfil a proportion of what that idea is, because he is only one man in one time playing for one team – and he is not a rugby player, rower, artist or opera singer, all of which might be described as reflecting greatness in a different way.  The meaning of attributes ascribed to earthly things has a proportional relationship with the meaning of divine attributes.  Again, the shared meaning (analogy) is not a large one, but it can be rationally described.

Aquinas’ analogical approach to religious language is a much better approach to religious language than the Via Negativa because it enables believers to use and defend the meaning of positive claims about God, while not supporting naïve univocalism or a philosophically unsatisfying and ultimately limited concept of God.  Aquinas’ model of God is deeply appealing in that it is supported by real experience, but it also retains the “otherness” and unlimited idea of God that is so important to believers.  Aquinas’ theory of religious language completes his model of God because it shows how believers are worshipping in an ultimately meaningful way, even though God is beyond ordinary understanding.  The Via Negativa is not the best approach to religious language because Analogy is a much better approach. 

Scholars who employ cataphatic theology and approach religious language through the Via Positiva reject the Via Negativa on the grounds that it ignores the important connection between God – the creator – and the world – the creation.  In the same way that Philosophers reason from movement, causation, contingency, grades of perfection in things, order and purpose to the existence of a necessary being who explains these qualities we experience in the universe, people should be able to apply words based on qualities we experience in the universe to the God who created them.  Anselm and John Duns Scotus both defended the univocal use of religious language on these grounds, arguing that words refer to concepts which depend on God to define them through His creation.  Anselm’s ontological argument depends on this argument, because it analyses the definition of God and finds necessary existence within it.  This could not work if the word “greater” meant anything different when applied to God than it does when applied to things in this world.  The problem with the univocal approach to religious language is that the type of connection between creator and creation does not support a literal approach to the meaning of language.  When a person creates something, their creation does not have to be like them.  The potter is not made of clay and a skilled potter is capable of making a bad pot. We have no reason to believe that words apply to God in exactly or even much the same way as they apply to things in this world.  Aquinas strict limitations on the sense in which meaning should be understood when words are applied to God seems much more realistic in relation to a God whose relationship with the world is understood to be the creator, Prime Mover, uncaused cause, necessary being, supreme perfection and intelligent designer.   Because of this, the Via Negativa is a better way to approach religious language than the Via Positiva, but it is still less good than Analogy.

Certainly, the Via Negativa has its uses, but these are more apparent when it comes to Philosophy or the practice of personal spirituality than they are in the practice of religion.  The word “religion” refers to what binds us as people together; the ties that bind need to be clearly defined and understood if they are to function and endure. In terms of Philosophy, approaching the nature of God through negation is an important check in naïve literalism.  As Maimonides wrote “it is of great advantage that man should know his station, and not imagine that the whole universe exists only for him.”  For philosophers, it is all too easy to move from saying that there are absolute limits to human knowledge to ignoring what lies beyond those limits to denying that there is anything beyond those limits to denying that there are limits.  As philosophers and as individuals, reflecting on the nature of God as “wholly other” forces us to confront the falsity of the prevalent assumption that “man is the measure of all things” and deepen their spiritual understanding, which includes confronting limitation and embracing humility.  As Tertullian said “our very incapacity of fully grasping Him affords us the idea of what He really is…”  and as St Cyril said “in what concerns God to confess our ignorance is the best knowledge…”  Certainly, the Via Negativa is a useful brake on naive literalism and a spiritual tool for individuals, but it cannot be described as the best approach to religious language in general.

In conclusion, the Via Negativa is far from being the best approach to religious language, although it is still useful in some ways. The best approach seems to be Aquinas’ doctrine of Analogy, which treads the line between acknowledging the otherness of God and retaining the ability to say some meaningful things about God successfully.  Ian Ramsey’s suggestion that words being used in an analogical sense should be signposted or qualified in some way seems a sensible way of improving Aquinas’ analogy further, avoiding the probability that believers could miss the careful sense in which words are being applied to God and confuse religious language with ordinary language.  Thomist scholars such as Gerry Hughes SJ use the word “timelessly” as such a qualifier, showing that words such as “good” should not be taken to mean more than can be defended in relation to the being and attributes of God and as proportional to His qualities.