i have my own pet theory for what "there is freedom in the dark--once someone has illuminated it" is about and it's based on a pamphlet from 1650 called "a single eye" by laurence clarkson, a radical dissenter of the time. as far as i can tell the thrust of the argument is that to "make darkness light" in the biblical sense is to collapse the duality of light and darkness and reveal them to be one thing--along with god and satan, virtue and sin.
"And that the more, I find these unfoldings of God in this, seem to appear contrary to most that is quoted in the History; I will make darkness light; How is it possible, when there is no communion, no correspondency but enmity? Yea, so great, that they cannot dwell in one house, lodge in one bed, but devour one another; for where darkness is, light is not, and where light appeareth, darkness is gone; yet notwithstanding you hear, he will make darkness light.
So that the first thing I mind from hence is, That he will not take darkness away, and in the room thereof place light, but that which in Scripture is called darkness, and by the creature believed darkness, shall be made light."
"Thirdly, Why it is called darkness, is but only in reference to the creatures apprehension, to its appearance; so nothing but imagined darkness: therefore his meaning is, that which appeareth now under the form of darkness, shall ere long appear in a Visage of light, as saith the Text, I will make darkness light before them."
to clarkson, the difference between these things is socially constructed by the church and by the law.
"So that yet, notwithstanding that, I must tell you as before I have related, that as all powers are of God, so all acts, of what nature soever are produced by this power, yea this power of God: so that all those acts arising from the power, are as Pure as the power, and the power as Pure as God.
So from hence it comes, there is no act whatsoever, that is impure in God, or sinful with or before God."
i thought it was particularly interesting because even among other english radicals clarkson was a bit of an outlier for being explicitly in favor of what he says the unenlightened call adultery. the sin comes only from the self-blame of the person who commits the act--or perhaps you could say their shame.
"When as a man in purity in light, acts the same acts, in relation to the act, and not the title: this man [no this man] doth not swear, whore, nor steal: so that for want of this light, of this single pure eye, there appeareth Devil and God, Hell and Heaven, sin and holiness, damnation and salvation; only, yea only from the esteemation and dark apprehension of the creature.
I will make darkness light, rough ways smooth; not half light and half darkness, not part rough and part smooth; but as it is said, Thou art all fair my Love, there is no spot in thee. Observe, all fair my Love; in thee only is beauty and purity, without, defilement: my love my dove is but one, thou one, not two, but only one, my love: Love is God, and God is Love; so all pure, all light, no spot in thee."
"No matter what Scripture, Saints, or Churches say, if that within thee do not condemn thee, thou shalt not be condemned; for saith the history, Out of thine own mouth, not another's, will I judge thee: Therefore, remember that if thou judge not thyself, let thy life be what it will, yea act what thou canst, yet if thou judge not thyself, thou shalt not be judged; For, I came not into the World to condemn, but to save the World. But if the reproach and slander of saints and churches do cause thee to question thyself, then art thou ready to say within what they report without, I am guilty of what they accuse me: So that true is the saying, O Adam, thy destruction is of thyself."
i wouldn't stake my life on this being factored into black sails or anything but i do think--given that they do namedrop the levellers and their Pamphlets--that it's possible, and it's fun to know that this attitude and the language used to describe it is historically accurate :3