Pythagorean parrots (appeal to authority)
An general image of the "appeal to authority" argument, from Glass Bentley's 1958 article “Liberal Education in a Scientific Age, meant to illustrate the state of education system in America. [2]
In debates, appeal to authority, or “argument from authority”, related to credentialism, refers to the discredited practice of attempting to decide whether or not a proposition is true, solely based on what an authority as said, or the weighted consensus of authorities have said, e.g. it took only one Copernicus, who used reason, logic, and measurements, to overthrow the weighted consensus of every authority around him and antecedent him.

Quotes
The following are related quotes:

“I myself tend to disapprove of the alleged practice of the Pythagoreans: the story goes that if hey were maintaining some position in an argument, and were asked why, they would reply: ‘the master said so’, the master being Pythagoras.”
Cicero (45BC), On the Nature of the Gods (§1, pg. 6) [1]

“When we engage in argument we must look to the weight of reason rather than authority. Indeed, students who are keen to learn often find the authority of those who claim to be teachers to be an obstacle, for they cease to apply their own judgment and regard as definitive the solution offered by the mentor of whom they approve.”
Cicero (45BC), On the Nature of the Gods (§1, pg. 6) [1]

“Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.”
Leonardo da Vinci (c.1500), Publication

“Those who rely simply on the weight of authority to prove any assertion, without searching out the arguments to support it, act absurdly. I wish to question freely and to answer freely without any sort of adulation. That well becomes any who are sincere in the search for truth.”
— Vincenzo Galilei (c.1560), advise taught to his son Galileo

References
1. Cicero. (45BC). The Nature of the Gods (Introduction, translation, and notes: Patrick Walsh) (pg. xxvi). Oxford University Press, 1998.
2. Glass, Bentley. (1958). “Liberal Education in a Scientific Age” (§: “The Present Divorce Between Science and the Humanities”, pg. 348), Bulletin of the Atomic Scientists, pgs. 346-53, Nov.

See also
Appeal to nature

External links
Appeal to authority – Wikipedia.