Assumption and Presumption
We can presume, from previous lessons, previous trials and errors, learning from past mistakes, that certain behavior will produce certain results. It is not certain though, hence it’s a presumption, due to the nature of free will choice. Not every action will produce the same result in a free will causal agent. But, the tendency, the probability, for the same effect to occur given the same cause and same circumstances, are nearly 100% statistically, void of the free will component. This is how cause and effect work. Presume is pre + sumere, to take before. The anticipation of something to happen can be true or false, and this largely varies depending on the interactivity with causal agents, especially free will causal agents. Presumption is mostly used in a negative context for taking something for granted, “taking upon oneself more than is warranted”, because it has been taken before the reality indicates what the reality actually is, and most of the time people “predict” and “anticipate” incorrectly.
Assumptions can be wrong or right as well. Assume is ab + sumere, to take up, to take to, to take in relation to, to take near. Taking something implicitly (inferring, deriving, deducing) from what was given explicitly (what the person directly conveyed in that message). Assumptions actually have data from reality that provide the inner implicit message, while presumptions are made before the data from reality is given. Assumption is kind of like reading between the lines. Instead of taking up something from existing data, a presumption is anticipated taking of something before someone gives you the information for you to infer the implications you derive. You are imagining too far ahead and incorrectly, creating a false image. It is an error in thinking, a fallacy.
Both assume and presume are understood in general as to take something for granted, as we can see in the etymological development, but they originally have the distinction I am elucidating. For the most part, people use them both in the sense of someone being wrong, but the presumption, with pre-, refers more to the negative form of an assumption that is taken before enough data is given to even consider that conclusion valid. Presumptions are more prone to being false as there is basically no data to even support the conclusion. Assumptions can be false because the inference can be incorrect, as the data used may be too weak to really derive anything, but it may also be correct. Presumptions are a prediction, anticipation or expectation, using no data or false reinventions, re-imaginings of data, or bad interpretations of receiving the message, or semantic misunderstandings on either or both the sender and receiver of a message.