He was talking about not accepting what other people say, but understanding it for yourself, and by the way, when he said it, he wasn't yet President. (Speech at Springfield, June 26, 1857)
Notice that Jackson does not mention the military, but only the civilian branches of government. There is a reason for that.
I guess you missed that second part where he said:
"Each public officer who takes an oath to support the Constitution swears that he will support it as he understands it and not as it is understood by others."
LOL. This is too funny. You're the who believes the military can impose its interpretation of the constitution on the civilian branches of government, and you're calling me fascist?
I am the one that believes the Military has an obligation to Defend our Constitution as they swore, and one of the requirements of this should be to make Damned certain that they are following a legitimate commander. Requiring him to Produce his paperwork is not optional in the performance of this duty.
Do you even know what fascism is? I'll give you a hint. In fascist countries, the military is usually not subserviant to civlian government, but rather the opposite, as you would seem to favor.
Yes, they just blindly follow orders without question, the way you advocate. Fascism is indicated by an unholy and far too intimate relationship between government and Business, accompanied by the production of political propaganda and the use of "brown shirts" to quell dissent. In other words, something very similar to what we have been seeing a lot of recently.
Actually, the opposite is true. You are asking the military to violate their oaths, since you are asking them to do something they are not most emphatically NOT constitutionally authorized to do, namely, to challange the civilian branches of government in their determination of the president's legitimacy.
and one of the requirements of this should be to make Damned certain that they are following a legitimate commander.
Perhaps in your mind that should be the case, but it most ephatically is not. Nothing in the constitition gives the military the authority to make a determination about their commander's legitimacy. That is the job of the electors, the legislature, the judiciary, and, ultimately, the people.
For the military to contravene the determination of two civilian branches of government, plus the electoral college, and the voters to boot, would be a violation of their constitutional oath of the grossest sort, if not outright treason.
"Each public officer who takes an oath to support the Constitution swears that he will support it as he understands it and not as it is understood by others."
The term "public officer" refers to an officer in the civilian government, not the military.