John Milton, when mourning in Paradise Lost the loss of his sight, concludes thus:

So much the rather thou Celestial light
Shine inward, and the mind through all her powers
Irradiate, there plant eyes, all mist from thence
Purge and disperse, that I may see and tell
Of things invisible to mortal sight. (III.51–55)

The sight of the Christian is unlike that of the non-believer in that God’s eyes take the place of his mortal ones and by them he sees in everything that reality which is “invisible to mortal sight.” This hymn, which comes to us from eighth-century origins, celebrates the utter revision which Christianity makes on a person. He comes to see that everything in heaven and on earth, in the mind of man and in the course of events, is God’s. All that we know of is directly linked to the person of God. The famous opening phrase of the hymn sums up this total sovereignty by asking God to be our vision. By this, the poet means not so much that God would help us to see, but that God would be all that we see. This is confirmed in the second line of the first stanza which puts God not only above all other earthly interests but asks him to push out all other interests but our interest in Him.

Having introduced our general petition in the first stanza, the poem in the middle stanzas proceeds to apply it to three areas of life that humans have commonly idolized. Wisdom (stanza 2), power (stanza 3), and riches (stanza 4) together summarize the common lusts of our visually-impaired race. In truth, they are the three attributes of the Lamb first listed in Revelation 5:12 (see also Eph. 1:17–19), but, in our rebellion, we look to and adore distortions of these things rather than the Lamb in whom alone they can be found. True wisdom is God’s wisdom, which we can only learn from his word, as a son learns from his father. “Hear, O sons, a father’s instruction, and be attentive, that you may gain insight” (Prov. 4:1). Likewise, true power is God’s power. In the third stanza we learn that our defence in battle (likely to be understood as spiritual) is God, but so is our glory in victory—here described as “dignity.” Beautifully modelled after the Psalms, the poem describes God both as shelter and tower, the latter image becoming a support by which we are raised to heaven. Finally, true riches are God’s riches: “his glorious inheritance in the saints,” as the Apostle Paul put it. Riches of the worldly sort are no interest to us, but the spiritual treasure of God certainly is. “Let not the wise man boast in his wisdom, let not the mighty man boast in his might, let not the rich man boast in his riches, but let him who boasts boast in this, that he understands and knows me, that I am the Lord” (Jer. 9:23).

The last stanza confirms God as the only one who can give us heaven’s joys. Whether we are meant to take these joys here on earth or actually in heaven is not explicit from the hymn. We may be inclined to take the last verse as solely about our glorification, but we need not. God is the high king of heaven and he is our victory won, so we need not read an implied future tense. The poem concludes, then, by reprising the general petition of its opening, with the same imagery as before of light (“O bright heav’n’s Sun”), heart (“Heart of my own heart”), and vision (“still be my vision”), in echoes of the Apostle Paul’s prayer that the “eyes of our hearts” be enlightened (Eph. 1:18).

The union of this text with the old Irish folk tune SLANE is a happy one. At first glance the melody may seem a bit wandering because it lacks the direct repetition and parallelism that one normally expects in tunes of this length, but the melody achieves a different kind of coherence based on the interrelatedness of its material and its overall shape. To see the tune’s connectedness its four phrases are best compared one atop the other. For convenience, we will refer to each measure in terms of its phrase number and letter of measure therein (i.e. the tune’s first measure would be 1A).

Phrase 1

Phrase 2

Phrase 3

Phrase 4

1C is the same as 1A, but missing the ornament on the measure’s last beat. 2A follows on in the same vein, only a step higher and even more static. Notice how 2B and 2C relate—one is up a step and then a leap, the other is down a step and then a leap. All the while, the tune’s range is growing upward and upward toward phrase 3. 3A is really related to 1A, 1C, and 2A, this time with more ornament added in the last two thirds of the measure for the climactic description of God in relation to ourselves placed at the beginning of the third line in every stanza. 4A is the one instance where leap follows on leap, and this gesture (unusual in old tunes) creates nice relationships with the text. On it we find words like “waking,” and phrases like “raise thou me” and “High King.” In all instances the idea of ascent (which the tune there quickly does) is fitting.

If we step back to consider the overall shape of the melody, we find it no less satisfying than the details already noted. Phrase 1 rises from “do” to “mi” (beginning and ending with what music theorists call tonic harmony) via a downward arc. Phrase 2 answers phrase 1 by rising from “re” to “sol” (beginning and ending with dominant harmony) via an upward arc. Then, after the climactic ornament of 3A, phrase 3 plummets from “la” down more than an octave, so that phrase 4 can begin and end on “do” with an upward arc. Thus a lovely, early-medieval, Irish prayer has been set to a tune that also happens to be Irish and old, that seems to fit the meaning of particular words and phrases in the prayer, and that is beautiful in its own right.