Syntheses for salicylic acid were developed. Finally, it was found that acetylation improved the properties even more and we now have aspirin. Aspirin itself has been improved by combination with buffers and other compounds. Every step along the way was an advance in the use of crude salicylic acid extracts and could have been the subject of a valid patent. While the public had to pay a royalty or wait for expiration of each patent before using the new knowledge, as each patent expired, the public was free to use the knowledge therein.
Patents are only the gateway to commercialization.
The patent owner tries to establish a period of exclusivity for a saleable version of the invention in which to recover research and development investment. Controlling or outlawing patents that are considered by special interest groups to be exploitative or even blasphemous may not stop development of a truly valuable product, but rather may drive it underground to be used within a single company as a trade secret. If so, the public will never gain the benefit of the invention, a benefit that could potentially extend far beyond the term of a patent, as in the case of generic drugs such as tetracycline or diazepam. Slamming the patent gateway shut, therefore, is both an overreaction and an ineffective reaction. There are other, less draconian methods of achieving desired social goals.