The quote was taken from a 1998 meeting of the National Bar Association wherein Thomas addressed black lawyers.
Here is one source though it is worded slightly differently.
Is this the actual quote? "but rather to assert my right to think for myself, to refuse to have my ideas assigned to me as if I were an intellectual slave because I'm black."
I wanted to use what you claimed as a Clarence Thomas quote but when I searched for verification of it, all I could find was your made up one, and that you have been trying to create it here at FR for 7 years worth of posts.
You can't just make up quotes like that.