Since I encountered the idea in 1987, I have found it very difficult to grasp what Charles Williams meant by the Way of Affirmation, or Via Positiva.
This is not surprising in itself for two obvious reasons. The first is that I was far from being a Christian at that time (much further away than I imagined); the second is that it is always hard to understand Charles Williams on any subject!
What I gathered was that he was putting forward a life of poetry and engagement with life - with the world and especially romantic love - as an alternative spiritual path, in contrast to the more obvious (and more obviously effective) negative path of withdrawal from the world, discipline of the mind and body and in general asceticism.
Also related to this is the idea that there may be a way to God via Joy and embrace of mystical union as well as the more familiar path of awareness of sin and repentance.
(Of course these paths are emphases rather than absolutes, there is always some mixture. Even an ascetic Saint requires some minimal conditions for the sustenance of their life.)
The dangers of this line of thought are obvious. In general, young men don't need much encouragement to pursue a life of pleasure and call it joy, of sexuality and call it romance, of self indulgent hedonism and call it union with the divine!
Yet to state the hazards does not invalidate the idea, since the hazards are great along the other path: especially spiritual pride or prelest.
Yet the idea of the positive way still seems vague, its success unsure and its relationship to the tried and tested and effective negative way unclear.
My current thoughts are as follows:
The negative way is essential to a Christian life. It is essential that each Christian begins with an awareness of the sinfulness - that is to say the worldliness, selfishness and gratification-seeking - of human life as such. It is essential that this be repented, and that the Christian ask God (via Christ) for forgiveness. It is essential, also, that some degree of control over worldly motivations be attained - some degree of asceticism - else the Christian will be merely a leaf in the wind of chance and circumstance.
So the negative way must come first.
Beyond that perhaps requires a recognition of individuality.
I am unsure whether the positive path of affirmation reaches as high as the negative ascetic path: I know that the negative path leads to Sainthood, to an earthly life lived in heaven. I don't know whether the positive path can attain that. I don't know whether there were affirmative Saints.
Yet for an individual it may be possible that the way of affirmation may take them higher than asceticism.
What does the via positiva aim to do?
I think it relates to the method used for orientating towards God.
The positive way tries to move towards communion with God via the activities of life: via Love and Work, especially.
This is sometimes expressed as consecration of these activities to God.
Crudely, this might be done by (in effect) interrupting these activities by periods of reflection and prayer - but this is in fact to 'stop doing' the activity of loving or working for the duration of reflection and prayer, so is clearly unideal.
Attention can be only one place at a time, so this suggests that the consecration of love and work to God should not be a matter of self-awareness but be implicit.
And, given that spiritual striving should be continuous, it further suggests that the way of affirmation would need to establish a context of prayer for the activities of life. Not so much a background, as a permeating environment of prayer.
And this seems to point back to something like the formation of a habit of continuous use of the Jesus Prayer or other short prayers used with multiple repetitions (although other methods are imaginable).
Such matters are explained and described in Unseen Warfare as translated into English from the Russian version by Starets Theophan the Recluse:
The method was invented of saying short prayers, which would keep the thought of straying, nor of going outside. St. Cassian speaks of this, saying that in his time this practice was general in Egypt (Dicourses x.10). From the teachings of other fathers we see that it was used on Mount Sinai, in Palestine, In Syria, and in all other places throughout the Christian world.
What other meaning have the invocation: ‘Lord have mercy!’ and other short prayers, which fill our divine services and our psalmody? Thus, here is my advice: choose for yourself a short prayer or several such prayers, and by repeating by themselves on your tongue, and keep your thought focused on one point only-remembrance of God.
Everyone is free to choose his own short prayers. Read the Psalms. There you can find in every Psalm inspiring appeals to your state and most appeal to you.
Learn them by heart and repeat now one, now another, now a third. Intersperse your recital of prayers with these, and let them be on your tongue at all times, whatever you may be doing, from one set time of prayer to another. You may also formulate your own prayers, should they better express your need, on the model of the 24 short prayers of St. Chrysostom, which you have in your prayer book.
But do not have too many, lest you overburden your memory and lest your attention runs from one to the other, which will be totally contrary to the purpose for which they were designed- to keep attention collected. The 24 prayers of St. Chrysostom is the maximum; one can use less.
To have more than one is good for variety and to enliven spiritual taste; but in using them one should not pass from one to another too quickly. Taking one which corresponds best to your spiritual need, appeal to God with it until your taste for it becomes blunted.
You can replace all your psalmody, or part of it, by these short prayers; make it a rule to repeat them several times- ten, fifty and a hundred times, with lesser bows. But always keep one thing in mind- to hold your attention constantly directed towards God.
We will call this practice short prayerful sighings to God, continued at all moments of the day and of the night, when we are not sleeping.