Nick Fotion in The Philosopher's Magazine:
Back in 1981, R.M. Hare, in his book Moral Thinking, featured a distinction that today I still find useful. Hare admitted that the distinction was not original with him, but he argued that philosophers have not appreciated its importance. The distinction is between critical and “intuitive” (what I call non-critical) thinking. It is still important since it reminds us not to make the mistake of focusing too much attention on the critical level. Philosophers are prone to make this mistake because they like to look critically at the norms their society holds to. Their critical outlook leaves the impression that thinking in ethics is mainly critical or reflective in nature. What they then fail to appreciate is that most ethical thinking takes place on the non-critical level. Indeed, it has to be that way since, otherwise, we would be spending all our energy critically examining one issue and then another. We would, thus, have no time to carry out our responsibilities at home and work; and no time for play.
Another bad consequence of taking the critical level too seriously is that we would quickly all turn into skeptics. Skepticism has its place in philosophical thinking but it can turn into a vicious philosopher’s game. Non-critical thinking can’t be all wrong since the rules and principles found there are part of what some philosophers call the common morality. It is the morality that, if it were questioned too seriously, would lead to social disintegration. Instead of questioning it all of the time, the critical/non-critical distinctions reminds us to pay more attention to the common morality so that we understand how it can be used to educate our children and to remind adults and children alike of their responsibilities when they are tempted to stray from the fold.
Another reason the distinction between critical and non-critical thinking was and is important becomes evident when we observe philosophers engaging in theory criticism. It is quite common for critics of utilitarianism, for instance, to insist that utilitarians must always be making utilitarian calculations. To be sure, act utilitarians may be addicted to calculating. But rule utilitarians can restrict their calculating ways to the critical level. On that level, they can generate new rules and modify old ones using their calculative skills. But having done that, they can place these criticised rules on the non-critical level and proceed to cite them in ways that make them sound like deontologists rather than true utilitarians.
The critical/non-critical levels distinction is useful not only in showing how utilitarianism is misunderstood, but also in making it clear how utlitiarianism is a much more flexible theory than many philosophers suppose.