I feel like the first one is at least partially unfair. It seems more like a noisy signal, since there are many appropriate uses of the phrase, such as: “It is obvious that the trajectory of this projectile as it passes through the atmosphere of Earth can be calculated with sufficient precision to predict its landing zone and evacuate persons in the area, therefore we will not elaborate on this. We will instead concentrate our efforts on methods of early detection and measurement of such dangerous objects.”
The alleged “obvious” statement draws from established and relatively confirmed experience, and may be assumed to be a fact that every physicist / astrophysicist / relevant expert already knows.
The same goes for most semantic stop signs. “If you want to reduce caloric intake, you should drink less soda.” Another way to state what you just said is “In the past we calculated similar trajectories, so we can be sure to calculate the trajectory of this object now.” The use as semantic stop sign comes from the fact that if something is obvious it does not need to be stated. The only people surprised and intimidated by stating that something is obvious are the exact people who do not think a point is obvious.
The use as semantic stop sign comes from the fact that if something is obvious it does not need to be stated.
There are times when it’s useful to state things that everyone present already knows. Most of the uses of “it’s obvious” fall out of these cases.
For example, the rules of formal argument in an academic context might normally require each step to be given in full; but for pedagogical purposes it’s not always useful to do that. The phrase there means you’re temporarily lowering the level of rigor to make the argument clearer or to save time, and that’s a useful thing to have in your toolbox.
Alternately, if you’re making a complex argument with a lot of moving parts, salience issues often come into play; your audience might need to be periodically reminded of certain simple facts, but stating them without qualification might be viewed as condescending. “It’s obvious that...” in this case serves as a social lubricant, a way of saying “I know you know this”.
I feel like the first one is at least partially unfair. It seems more like a noisy signal, since there are many appropriate uses of the phrase, such as: “It is obvious that the trajectory of this projectile as it passes through the atmosphere of Earth can be calculated with sufficient precision to predict its landing zone and evacuate persons in the area, therefore we will not elaborate on this. We will instead concentrate our efforts on methods of early detection and measurement of such dangerous objects.”
The alleged “obvious” statement draws from established and relatively confirmed experience, and may be assumed to be a fact that every physicist / astrophysicist / relevant expert already knows.
The same goes for most semantic stop signs. “If you want to reduce caloric intake, you should drink less soda.” Another way to state what you just said is “In the past we calculated similar trajectories, so we can be sure to calculate the trajectory of this object now.” The use as semantic stop sign comes from the fact that if something is obvious it does not need to be stated. The only people surprised and intimidated by stating that something is obvious are the exact people who do not think a point is obvious.
There are times when it’s useful to state things that everyone present already knows. Most of the uses of “it’s obvious” fall out of these cases.
For example, the rules of formal argument in an academic context might normally require each step to be given in full; but for pedagogical purposes it’s not always useful to do that. The phrase there means you’re temporarily lowering the level of rigor to make the argument clearer or to save time, and that’s a useful thing to have in your toolbox.
Alternately, if you’re making a complex argument with a lot of moving parts, salience issues often come into play; your audience might need to be periodically reminded of certain simple facts, but stating them without qualification might be viewed as condescending. “It’s obvious that...” in this case serves as a social lubricant, a way of saying “I know you know this”.