I was reading Niccolo Cabeo's Philosophia Magnetica (1627), p. 180 and found this line:
...quicquid reclamet Aristoteles: non est non ens scire.
The context is regarding experiments, and how some philosophers were deluding themselves by searching for causes or reasons for things, but those causes did not exist. (Specifically, it's a response to electricity, as some people tried to explain why chaff and straw were the only things attracted by amber, but in fact all materials were actually attracted.)
I think the translation would literally be:
There is no nothingness to know.
But a more relaxed (and possibly incorrect) translation could be:
There is nothing to know from nothing.
I haven't heard this quote from Aristotle before. What does it mean, and where is it from? (The second question might be better suited to e.g. history of math and science SE, question can be edited if anyone wants.)