So, if I think a car will just go right through me and I will be unharmed then I should just walk right out onto any highway, right?
Of course not.
If you want to mentally masturbate, you can go into solipsistic arguments. You can ask how do we know that we know until absolutely nothing is certain. While it may be an entertaining game, it's nothing more than playing with your own mind, pushing symbols around in accordance with certain rules.
We all know that cars exist for real and that walking out in front of one going 60 mph will likely get you mangled and/or killed. I know this for certain, because my brother did it while on drugs that made him think, delusionally, that he'd be ok. Well, guess what? Reality 1, Belief 0. Luckily, my brother is still alive, but his body has been screwed up and he's got brain damage. Or maybe he hasn't. Maybe that's just my subjective experience.
There are certain facts of life that for all practical purposes are objective. Emphasizing that because we experience these objective events through our subjectivity is useful only in that it helps us be on guard against errors in judgment caused by the fallibility of our perceptual apparatuses. It is not carte blanche to believe any old crazy thing you want and, worse, say that it is just as valid as beliefs based on empirical evidence.
Would you inject yourself with some drug simply because somebody decided to believe, based on their own subjective criteria, that it would help you? Or would you want some scientific proof that the substance would help you instead of harming you? But wait... that's all just subjective brouhaha, right? So the studies and the crazy ideas of a lunatic are exactly the same....
Please.
You are surrounded by the validity of scientific thought in your everyday life. You might even have been dead by now were it not for this supposedly subjective pursuit.
Trust in science is based on evidence and reason. We have ample evidence to prove to us that the scientific method is necessary. One reason is that we're not perfect and that we don't know everything. So, we have to experiment, play around, and see if our guesses about the world are right or wrong.
