Exactly, but some scientists fail to see this difference, and when they collectively come to a conclusion from the same unstated premise (e.g. ideological affiliation), then we have a problem. In the AGW case, the obvious one is assuming that a global governmental solution is the only acceptable policy — this certainly didn’t come from the climate data. “Something must be done” does not equal “something must be done by X”, which BTW limits and hampers possible solutions and exclude many relevant actors. It’s like using the ‘consensus’  based on oberved data that many people starve in the world to conclude that governments should collect our food and send to them.  I actually don’t like this word, consensus for me is related to a centroid, or a center of mass.