IV.
Cloudy old prophets of the Porch[175] once taught
That sense and shape presented to the thought
From outward objects their impression take,
As when upon a paper smooth and plain
On which as yet no marks of ink have lain
We with a nimble pen do letters make.
But if our minds to nothing can apply
Their proper motions, but do patient lie
Subject to forms which do from bodies flow,
As a glass renders empty[176] shapes of things,
Who then can show from whence that motion springs
By force of which the mind all things doth know?
Or by what skill are several things espied?
And being known what power doth them divide,
And thus divided doth again unite,
And with a various journey oft aspires
To highest things, and oft again retires
To basest, nothing being out of sight,
And when she back unto herself doth move,
Doth all the falsehoods by the truth reprove?
This vigour needs must be an active cause,
And with more powerful forces must be deckt,
Than that which from those forms, that do reflect
From outward matter, all her virtue draws.
And yet in living bodies passion's might
Doth go before, whose office is to incite,
And the first motions in the mind to make.
As when the light unto our eyes appears,
Or some loud voice is sounded in our ears,
Then doth the strength of the dull mind awake
Those phantasies which she retains within;
She stirreth up such notions to begin,
Whose objects with their natures best agree,
And thus applying them to outward things,
She joins the external shapes which thence she brings
With forms which in herself included be.
[175] The Porch, i.e. the Painted Porch ([Greek: stoa poikilae]) at Athens, the great hall adorned with frescoes of the battle of Marathon, which served as lecture-room to Zeno, the founder of the Stoic sect.
[176] Cf. Quin potius noscas rerum simulacra uagari Multa modis multis nulla ui cassaque sensu.
"But rather you are to know that idols or things wander about many in number in many ways, of no force, powerless to excite sense."—Lucr. iv. 127, 128 (trans. Munro).