“Dubito ergo cogito, cogito ergo sum”
This was the original.
We have chosen to keep only ‘cogito ergo sum’ and be extremely proud of the fact humans are the only animals able to reason.
There is a small video that makes me wonder.…(You can enjoy all of it later, for the purpose of this post please watch from 28:01 to 32:00)
The way I see it, the monkey IS able to reason but is unable to refrain itself. When the situation allowed for ‘cold reasoning’ – when only numbers where involved, not real candy – he displayed the same kind of reasoning as the one we’d usually do.

By contrast, it is us, humans, who have the unique ability to think discursively – please see one of my previous posts about this – and hence the possibility to ask ourselves “what if?”
Maybe this is what Descartes wanted to convey to us, that it’s our capacity to ‘dubito’ that makes us humans, after all.

PS. Here you have the full transcription of that video.