The first four lines are from an untitled poem by ‘J. G.’, printed in 1748:
The following Lines were sent by a Gentleman a little deformed, to a young Lady he was
encouraged to pay his Addresses to; upon her saying, she would have no such ill-shaped Fellow as he.
’Tis true, my shape is something odd,
But blaming me is blaming God;
For had I spoke myself to birth,
I’d pleas’d the prettiest lass on earth:
And could I form myself a-new,
I would not fail of pleasing you.
J. G. (1748). The Universal Magazine, March 1748, p. 132.
The last four lines are from the poem ‘False Greatness’ (1698) by Isaac Watts. Here’s the third stanza, as printed in 1706:
Thus mingled still with Wealth and State
Crœsus† himself can never know;
His true Dimensions, and his Weight
Are far inferiour to their show;
Were I so tall to reach the Pole,
Or grasp the Ocean with my Span,
I must be measur’d by my Soul.
The Mind’s the Standard of the Man.
Isaac Watts (1698). ‘False Greatness’. In Watts (1706). Horae Lyricae: Poems, Chiefly of the Lyric Kind, p. 129. London: John Lawrence.
† Croesus was king of Lydia in the 6th century BCE. His mint was credited with issuing the first coinage of pure gold, and his name became a byword for wealth.
You can see that the lines have been altered in ways characteristic of memorization and recall, for example, in the quotation from ‘J. G.’, “form” has replaced “shape” in the first line, perhaps causing “form” to become “create” in “form myself anew” to avoid a repetition.
Joseph Merrick, the “Elephant Man”, found these two poems apposite to his situation, and seems to have quoted from them often. In The True History of the Elephant Man by Michael Howell and Peter Ford (1980, Penguin), the authors include two short pieces by Merrick. At the end of appendix one, ‘The Autobiography of Joseph Carey Merrick’, Merrick quotes from Watts (p. 184) and at the end of appendix two, “amplified from an account in the British Medical Journal”, Merrick quotes from both (p. 189). Merrick’s habit of quoting these two quatrains next to each other without attribution must have given rise to the idea that they were original to him.