Can inventions in all fields be patented?

The patent system is a system to protect inventions, but it does not mean that all inventions in the world can be protected by the patent system. Every country in the world will set up a list from the aspects of operability, public order or industrial policy, and exclude some objects that are not suitable for protection through the patent system.

It should be noted that different countries have different understandings of public order, and the meaning of public order will also change in different periods in the same country. For example, in France, gambling tools can be patented, but not in China and Japan.

In addition, being granted a patent right does not mean that the patented product can circulate freely in the market. New fighters, tanks and cannons can all be patented, but these weapons obviously cannot circulate freely in the market. In addition, even if the drug is patented, it still needs marketing approval before it can be used for clinical treatment.