There are many people out there who assert that physics and science is just a man made invention, made by convention. They say a bunch of people just decided and agreed to say that the laws of physics are what they are and that since it was all just made up arbitrarily, this means it may not be true. These types usually have a religious motive for taking such a stance on science. So what are your thoughts on this? how do you respond to this kind of reasoning?