The superior mind. Seneca, Epistles 4.41.5-6

Seneca describes the superior mind, which refuses to give way when it encounters strong emotions. He says that such a mind will not shine, or take glory, in goods that don't belong properly to it (such as the goods that it receives from fortune, like a nice house or good health), and he illustrates this meaning by drawing attention to the difference between a fine animal (such as a horse or lion) and fine ornaments (which don't make the horse any better and actually ruin the aspect of the lion).

Animum excellentem, moderatum, omnia tamquam minora transeuntem, quidquid timemus optamusque ridentem, caelestis potentia agitat. Non potest res tanta sine adminiculo numinis stare; itaque maiore sui parte illic est unde descendit. Quemadmodum radii solis contingunt quidem terram sed ibi sunt unde mittuntur, sic animus magnus ac sacer et in hoc demissus, ut propius quidem divina nossemus, conversatur quidem nobiscum sed haeret origini suae; illinc pendet, illuc spectat ac nititur, nostris tamquam melior interest.

Quis est ergo hic animus? qui nullo bono nisi suo nitet. Quid enim est stultius quam in homine aliena laudare? quid eo dementius qui ea miratur quae ad alium transferri protinus possunt? Non faciunt meliorem equum aurei freni. Aliter leo aurata iuba mittitur, dum contractatur et ad patientiam recipiendi ornamenti cogitur fatigatus, aliter incultus, integri spiritus: hic scilicet impetu acer, qualem illum natura esse voluit, speciosus ex horrido, cuius hic decor est, non sine timore aspici, praefertur illi languido et bratteato.

A heavenly power stirs the superior mind: being well governed, it passes through all things as though they were trifles, laughing at anything we fear or desire. Such a marvel cannot stand without the support of a will more than mortal, and so the greater part of such a mind remains with its source, refusing to come all the way down to us. Even as the rays of the sun touch the earth but stay with the fire that sends them forth, so the great and holy mind, when it has been sent down to us, that we may know divinity more intimately, converses some with us but clings ever to its own origin. It hangs ever on heaven, looking and striving toward the divine, walking among us as one greater than we.

What is this mind, then? One that shines with no good but its own. For what is stupider in a man than praising things that don't belong to him? What more demented than marveling at things that can suddenly be carried over to another? Golden reins don't make a better horse. The lion goes differently when his mane is flocked with gold, his head bent from fatigue as men force him to bear the weight of a heavy ornament. Not so when he walks uncombed, his spirit whole and free: then he is keen to pounce, as the cat that nature made him, splendid in his shagginess, which has this native charm, that it cannot be seen without fear. Certainly the wild lion is more compelling than the listless one loaded with gold.