Reason may be "too Young to rule a Flame" (of love)

— Blackmore, Sir Richard (1654-1729)

Reason may be "too Young to rule a Flame" (of love)
Metaphor in Context
The Prince of Spain, his Court assiduous made,
And still with Pleasure in her Presence staid.
The more he saw the more he did admire,
Till her bright Form possess'd his Soul entire.
Nor did he strive his Passion to disguise,
But the soft Accents of his melting Eyes,
The Eloquence of Looks and Vocal Mien,
Love's tender Diction, told it to the Queen;
Which in her Breast did anxious Care create,
Touch'd with the gen'rous Prince's rigid Fate,
Whose Reason was too Young to rule a Flame,
Which from a Spring approv'd by Vertue came,
And own'd a just, tho' unsuccessful Aim.
She view'd him like a Ship, its Rudder lost,
On swelling Waves by Winds tempestuous tost,
Despairing e'er to gain the wish'd-for Coast.
Searching "rule" and "reason" in HDIS (Poetry)
At least 1 entry in ESTC (1718).
A Collection of Poems on Various Subjects. by Sir Richard Blackmore, Kt. M. D. Fellow of the Royal-College of Physicians. (London: Printed by W. Wilkins, for Jonas Browne at the Black-Swan without Temple-Bar; and J. Walthoe, Jun'. over-against the Royal-Exchange in Cornhill, 1718). <Link to ECCO>
Date of Entry

The Mind is a Metaphor is authored by Brad Pasanek, Assistant Professor of English, University of Virginia.