Works of St. Anselm, tr. by Sidney Norton Deane, , at sacred-texts.com
To none of these is another necessary that he may remember, conceive, or love: since each taken by himself is memory and intelligence and love and all that is necessarily inherent in the supreme Being.
BUT, while this discussion engages our attention, I think that this truth, which occurs to me as I reflect, ought to be most carefully commended to memory. The Father must be so conceived of as memory, the Son as intelligence, and the Spirit as love, that it p. 120 shall also be understood that the Father does not need the Son, or the Spirit common to them, nor the Son the Father, or the same Spirit, nor the Spirit the Father, or the Son: as if the Father were able, through his own power, only to remember, but to conceive only through the Son, and to love only through the Spirit of himself and his son; and the Son could only conceive or understand (intelligere) through himself, but remembered through the Father, and loved through his Spirit; and this Spirit were able through himself alone only to love, while the Father remembers for him, and the Son conceives or understands (intelligit) for him.
For, since among these three each one taken separately is so perfectly the supreme Being and the supreme Wisdom that through himself he remembers and conceives and loves, it must be that none of these three needs another, in order either to remember or to conceive or to love. For, each taken separately is essentially memory and intelligence and love, and all that is necessarily inherent in the supreme Being.