Plutarch's morals. Part 2. translated from the Greek by several hands.

Question VIII. Why Old Men read best at a distance?

TO my Discourse in the former Problem some Objection may be drawn from the Sense of seeing in old Men; for if they hold a Book at a distance they will read pretty well, nearer they cannot see a Letter; and this Aeschyles means by these Verses,

Far off thou canst not see, nay, scarce behold When near; a proper Scribe now thou art old:

And Sophocles more plainly,

Old Men are slow in Talk, they hardly hear, For off they see, but all are blind, when near.

And therefore, if old Mens Organs are more o∣bedient to strong and intense Qualities; why, when they read, do they not take the Reflection near at hand, but holding the Book a good way off, mix, and so as Wine by Water, weaken it by the intervening Air? Some answered, that they did not remove the Book to lessen the Light,

but to receive more Rays, and let all the Space between the Letters and their Eyes be fill'd with lightsome Air. Others agreed with those that imagine the Rays of Vision mix with one another, for since there is a Cone stretcht between each Eye, and the Object, whose Point is in the Eye, and whose Basis is the Object, 'tis probable that for some way each Cone extends a part, and by it self; but when the distance increases, they mix, and make but one common Light, and therefore every Object appears single, and not two, though 'tis seen by both Eyes at once; for the Conjuncti∣on of the Cones makes these two Appearances but one; these things suppos'd, the old Men that hold the Letters near to their Eyes, the Cones not being joyn'd, but each part, and by it self, their Sight is weak; but those that remove it farther, that two Lights being mingled and increast, see better, as a Man with both Hands can hold that for which either singly is too weak: But my Bro∣ther Lamprias, though unacquainted with Hiero∣nymus his Notions, invented another Reason. We see, said he, by some Species that come from the Object to the Eye, which at their first rise are thick and great, and therefore when near disturb old Men, whose Eyes are not easily penetrated, and stiff; but when they are separated and dif∣fus'd into the Air, the thick obstructing Parts are easily remov'd, and the subtle Remainders com∣ing to the Eye, gently and easily slide into the Pores; and so the disturbance being less, the Sight is more vigorous and clear. Thus a Rose smells most fragrant at a Distance, but if you bring it near the Nose 'tis not so pure nor de∣lightful; and the reason is this, many earthy, disturbing Particles are carry'd with the Smell,

and spoil the Fragrancy when near, but in a longer passage those are lost, and the pure brisk Odor, by reason of its Subtlety, reaches and acts upon the Sense: But we, according to Plato's Opi∣nion, assert, that a bright Spirit darted from the Eye, mixes with the Light about the Object, and those two are perfectly blended into one si∣milar Body; now these must be joyned in due proportion one to another; for one part ought not wholly to prevail on the other, but both being proportionably and amicably joyn'd, agree in one third common Power. Now this (whe∣ther Flux, illuminated Spirit, or Ray) in old Men being very weak, there can be no Combi∣nation, no Mixture with the Light about the Object, but it must be wholly consum'd, unless by removing the Letters from their Eyes, they lessen the Brightness of the Light, and so it comes to the Sight, not too strong or unmixt, but well proportioned and blended with the other. And this explains, that common Affection of Crea∣tures of seeing in the Dark, for their Eye-sight being weak, is overcome and darkned by the Splendor of the Day, because the little Light that flows from their Eyes cannot be proportion∣ably mixt with the stronger and more numerous Beams; but is proportionable and sufficient for the Feeble Splendor of the Stars, and so can joyn with it, and cooperate to move the Sense.