A signal indicating that the cited source clearly supports the opposite of whatever the author just said, although an inference is required to see the contradiction. But see is the strongest negative signal after contra. Whereas contra indicates a direct contradiction, but see indicates a very likely contradiction.
Note that if a but see citation follows another cited source, the but see source will be construed as contradicting the previous source - and not the statements in the present piece of writing. Therefore, to prevent confusion, a but see citation should be converted into a see citation if it is placed after another source with a negative signal. For more on this rule, see order of signals.
See Negative signal.