Parallel - Ducdame's Greek invocation explained

The Ducdame parallel

from Shake-Speare's As You Like It 2.5.47-56

Jacques sings or speaks the following song:

If it do come to pass
That any many turn ass,
Leaving his wealth and ease,
A stubborn will to please,
Ducdame, ducdame, ducdame,
Here shall he see
Gross fools as he,
And if he will come to me.

The text continues:

Amiens:   What's that "ducdame"?
Jacques:  'Tis a Greek invocation to call fools into a circle.

now from Bacon: "It is a matter of common discourse of the chain of sciences how they are linked together, inasmuch as the Grecians, who had terms at will, fitted it of a name of Circle learning".
  Valerius Terminus or Of the Interpretation of Nature

Comment:  Jacque's answer has bemused editors to this day. To analyze some of the points, "ducdame" may be Gaelic for "Come to me". The conjunction of "Greek" and "fools" suggests that Shake-Speare may have had in mind the expression "foolish Greek" which he used in Twelfth Night 4.1.18 as slang for "silly merry-maker". "Merry Greek" was a familiar expression. But why does Jacques call the foolish Greeks into a "circle"? The Arden As You Like It editor thinks that Jacques may refer to the safe circle of Arden into which the Duke and his followers have retreated. More plausibly, she continues: "In stage performance the people to whom he is speaking often gather round him [Jacques], lured by his mysterious and portentious manner, only to break up in some discomfiture, as they realize that they have literally been drawn into a circle, and thus, in the manner of a playground joke, proved fools". Despite this possible explanation, I think it likely that Shake-Speare had (or had also) in mind the Greek Circle learning mentioned in the Bacon text (of which editors seem unaware). So erudite was Shake-Speare that if he thought of "Greek" and "circle", he would at once think of Greek Circle learning. Line 56 is then an ironic reference to that learning - instead of learned Greeks in a circle, there were "foolish Greeks" in a circle. Will Shakespere, incidentally, would hardly have made this connection. Shake-Speare cannot have derived Greek Circle learning from Valerious Terminus which was written later than the play.