Evagrius speaks of the highest form of prayer (“pure prayer”) – as having three qualities: (1) It is “unceasing” (1Thess 5.17), (2) it is “imageless” (forms no image of God in the mind), and (3) it is “wordless” (it passes beyond the limits of finite words and concepts).
My guess is that “images” and “words” are linked. “Words” are inseparable from “images.” When we reach a communion with God that is outside the mediation of all images, that communion will be wordless as well, ineffable (not an experience of God ‘in’ and ‘through’ and ‘in terms of’ relating to words and their meanings). That’s my sense of what Evagrius means by prayer being “free of thoughts.” To say X is to take a step away from X. Think about it. So long as our experience of God consists in saying things to God about him, we remain a step removed from being (experiencing ourselves as) immediately present with/to him. When you think about it, the same is true of intimacy with other people. If you mouth is open and you’re spouting words, you’re not as intimate as you might otherwise be.
Not to be misunderstood, Evagrius advocated praying with words too (using the psalms, praying Scripture, etc.), a lot. So it seems imageless/wordless communion with God was for him the goal, but we must use words to get there. “Wordless” prayer isn’t something we just up and decide to ‘do’, i.e., it is not a refusal to use words. Rather, it is where one arrives from exhausting language (not refusing to use it) in the contemplation of God, experiencing transcendence as one comes to an experience of oneself in/with God that words can neither comprehend nor express (“joy ‘unspeakable’ and full of glory”?). Denys Turner says it well:
…You cannot understand the role of the apophatic, or the extent to which it is necessary to go in denying things of God, until you have understood the role of the cataphatic and the extent to which it is necessary to go in affirming things of God.
…the way of negation is not a sort of po-faced, mechanical process, as it were, of serial negation, affirmation by affirmation, of each thing you can say about God, as if affirmative statements about God were all false; nor is it…simply adding the prefix ‘super’ to already superlative Latin adjectives predicated of God…. Rather…the way of negation demands prolixity; it demands the maximization of talk about God; it demands that we talk about God in as many ways as possible, even in as many conflicting ways as possible, that we use up the whole stock-in-trade of discourse in our possession, so as thereby to discover ultimately the inadequacy of all of it….
…the ‘way of negation’…is the encounter with the failure of what we must say about God to represent God adequately. If talk about God is deficient, this is a discovery made within the extending of it into superfluity, into that excess in which it simply collapses under its own weight.
Language ends but we keep going, not because language is false or untrue, but because there’s more to us (and God) than words. One still exists, just on the other side of the limits of finite images and words. This is why prayer is ultimately a subversive act in the world; it refuses to derive one’s essential value and identity from the politics or the market. “We” are more than words, so words have to fail at some point. For Evagrius, I think, it is only words in prayer that can get us to wordless prayer (the ineffable communion of the soul with God).
What I wonder about (and hope is true – because I love words and don’t want to give them up!) is whether when our experience of God escapes the confines of finite images and words, when we are comfortably wordless in God’s presence, we are still able to employ images and words to share, teach, celebrate with others, etc. Obviously this must be the case. That’s why mystical language (and poetry – and theology, at its best) strains the capacities of language so.