Who wrote the lines ..."oh what tangled webs they weave , those that
choose to deceive.." and which play do they come from?

Dear ree396,

The exact quotation is:

"Oh what a tangled web we weave,
When first we practise to deceive!"

Actually, these two lines derive not from a play, but from Sir Walter
Scott's (1771-1832) epic poem "Marmion" (1808), Canto VI, Stanza XVII:
http://www.bartleby.com/100/338.25.html [1]

You can read those lines in their full context here (scroll down to stanza XVII):
http://www.geocities.com/poeminister/canto6.htm [2]


Sources:

[1] Bartleby.com: Familiar Quotations - Sir Walter Scott (1771?1832)
http://www.bartleby.com/100/338.25.html

[2] Poeminister's Page: Marmion, A Tale of Flodden Field by Sir Walter
Scott - Canto 6
http://www.geocities.com/poeminister/canto6.htm

Shakesper 2004: Identify this quote?
http://www.shaksper.net/archives/2004/1644.html

Search terms used:
"what tangled webs" "walter scott"
://www.google.de/search?hl=de&newwindow=1&c2coff=1&q=%22what+tangled+webs%22+%22walter+scott%22&btnG=Suche&meta=
"what a tangled web" scott
://www.google.de/search?hl=de&newwindow=1&c2coff=1&q=%22what+a+tangled+web%22+scott&btnG=Suche&meta=


Hope this answers your question!
Regards,
Scriptor

Thank you for your prompt and explicit response- Excellent Service